From 50c30655d777ab068d912a08a931fd3a748d06b6 Mon Sep 17 00:00:00 2001
From: MumuNiMochii <deanharoldpabad@gmail.com>
Date: Tue, 11 Jan 2022 23:10:12 +0800
Subject: [PATCH] commit on 'answers'

---
 .../01_Scripts/01_Inline_Script/index.html    |  12 ++
 .../01_Scripts/02_Internal_Script/index.html  |  14 +++
 .../01_Scripts/03_External_Script/index.html  |  12 ++
 .../01_Scripts/03_External_Script/script.js   |   1 +
 .../04_Multiple_External_Scripts/index.html   |  13 ++
 .../04_Multiple_External_Scripts/main.js      |   1 +
 .../04_Multiple_External_Scripts/message.js   |   1 +
 .../02_Data_Types/01_Numbers/index.html       |  19 +++
 .../02_Data_Types/02_Strings/index.html       |  16 +++
 .../02_Data_Types/03_Booleans/index.html      |  15 +++
 .../02_Data_Types/04_Undefined/index.html     |  15 +++
 .../Answers/02_Data_Types/05_Null/index.html  |  15 +++
 .../06_Checking_Data_Types/index.html         |  26 ++++
 .../Answers/03_Variables/index.html           |  42 +++++++
 .../Answers/04_Exercises/datatypes.js         |  13 ++
 .../Answers/04_Exercises/index.html           |  67 +++++++++++
 .../Answers/04_Exercises/variables.js         |  13 ++
 .../01_Data_Types/01_Primitive/index.html     |  53 ++++++++
 .../01_Data_Types/02_Non-Primitive/index.html | 107 +++++++++++++++++
 .../01_Declaring_Number_Data_Types/index.html |  28 +++++
 .../02_Numbers/02_Math_Object/index.html      |  61 ++++++++++
 .../03_Random_Number_Generator/index.html     |  23 ++++
 .../Answers/03_Strings/01_Types/index.html    |  26 ++++
 .../03_Strings/02_Concatenation/index.html    | 113 ++++++++++++++++++
 .../03_Methods/01_length/index.html           |  18 +++
 .../index.html                                |  19 +++
 .../03_Methods/03_toUpperCase()/index.html    |  16 +++
 .../03_Methods/04_toLowerCase()/index.html    |  16 +++
 .../05_substr()_and_substring()/index.html    |  28 +++++
 .../03_Methods/06_split()/index.html          |  34 ++++++
 .../03_Methods/07_trim()/index.html           |  21 ++++
 .../03_Methods/08_includes()/index.html       |  22 ++++
 .../03_Methods/09_replace()/index.html        |  18 +++
 .../03_Methods/10_charAt()/index.html         |  20 ++++
 .../03_Methods/11_charCodeAt()/index.html     |  21 ++++
 .../03_Methods/12_indexOf()/index.html        |  22 ++++
 36 files changed, 961 insertions(+)
 create mode 100644 01_Day_Introduction/Answers/01_Scripts/01_Inline_Script/index.html
 create mode 100644 01_Day_Introduction/Answers/01_Scripts/02_Internal_Script/index.html
 create mode 100644 01_Day_Introduction/Answers/01_Scripts/03_External_Script/index.html
 create mode 100644 01_Day_Introduction/Answers/01_Scripts/03_External_Script/script.js
 create mode 100644 01_Day_Introduction/Answers/01_Scripts/04_Multiple_External_Scripts/index.html
 create mode 100644 01_Day_Introduction/Answers/01_Scripts/04_Multiple_External_Scripts/main.js
 create mode 100644 01_Day_Introduction/Answers/01_Scripts/04_Multiple_External_Scripts/message.js
 create mode 100644 01_Day_Introduction/Answers/02_Data_Types/01_Numbers/index.html
 create mode 100644 01_Day_Introduction/Answers/02_Data_Types/02_Strings/index.html
 create mode 100644 01_Day_Introduction/Answers/02_Data_Types/03_Booleans/index.html
 create mode 100644 01_Day_Introduction/Answers/02_Data_Types/04_Undefined/index.html
 create mode 100644 01_Day_Introduction/Answers/02_Data_Types/05_Null/index.html
 create mode 100644 01_Day_Introduction/Answers/02_Data_Types/06_Checking_Data_Types/index.html
 create mode 100644 01_Day_Introduction/Answers/03_Variables/index.html
 create mode 100644 01_Day_Introduction/Answers/04_Exercises/datatypes.js
 create mode 100644 01_Day_Introduction/Answers/04_Exercises/index.html
 create mode 100644 01_Day_Introduction/Answers/04_Exercises/variables.js
 create mode 100644 02_Day_Data_types/Answers/01_Data_Types/01_Primitive/index.html
 create mode 100644 02_Day_Data_types/Answers/01_Data_Types/02_Non-Primitive/index.html
 create mode 100644 02_Day_Data_types/Answers/02_Numbers/01_Declaring_Number_Data_Types/index.html
 create mode 100644 02_Day_Data_types/Answers/02_Numbers/02_Math_Object/index.html
 create mode 100644 02_Day_Data_types/Answers/02_Numbers/03_Random_Number_Generator/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/01_Types/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/02_Concatenation/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/03_Methods/01_length/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/03_Methods/02_Accessing_Characters_in_String/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/03_Methods/03_toUpperCase()/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/03_Methods/04_toLowerCase()/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/03_Methods/05_substr()_and_substring()/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/03_Methods/06_split()/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/03_Methods/07_trim()/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/03_Methods/08_includes()/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/03_Methods/09_replace()/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/03_Methods/10_charAt()/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/03_Methods/11_charCodeAt()/index.html
 create mode 100644 02_Day_Data_types/Answers/03_Strings/03_Methods/12_indexOf()/index.html

diff --git a/01_Day_Introduction/Answers/01_Scripts/01_Inline_Script/index.html b/01_Day_Introduction/Answers/01_Scripts/01_Inline_Script/index.html
new file mode 100644
index 0000000..3fb8766
--- /dev/null
+++ b/01_Day_Introduction/Answers/01_Scripts/01_Inline_Script/index.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Inline Script</title>
+</head>
+<body>
+    <button onclick="alert('Welcome to 30DaysOfJavaScript!')">Click Me</button>
+</body>
+</html>
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/01_Scripts/02_Internal_Script/index.html b/01_Day_Introduction/Answers/01_Scripts/02_Internal_Script/index.html
new file mode 100644
index 0000000..75f636f
--- /dev/null
+++ b/01_Day_Introduction/Answers/01_Scripts/02_Internal_Script/index.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Internal Script</title>
+</head>
+<body>
+    <script>
+        console.log('Welcome to 30DaysOfJavaScript')
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/01_Scripts/03_External_Script/index.html b/01_Day_Introduction/Answers/01_Scripts/03_External_Script/index.html
new file mode 100644
index 0000000..3ee4929
--- /dev/null
+++ b/01_Day_Introduction/Answers/01_Scripts/03_External_Script/index.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: External Script</title>
+</head>
+<body>
+    <script src="script.js"></script>
+</body>
+</html>
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/01_Scripts/03_External_Script/script.js b/01_Day_Introduction/Answers/01_Scripts/03_External_Script/script.js
new file mode 100644
index 0000000..7e9904d
--- /dev/null
+++ b/01_Day_Introduction/Answers/01_Scripts/03_External_Script/script.js
@@ -0,0 +1 @@
+console.log('Welcome to 30DaysOfJavaScript!')
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/01_Scripts/04_Multiple_External_Scripts/index.html b/01_Day_Introduction/Answers/01_Scripts/04_Multiple_External_Scripts/index.html
new file mode 100644
index 0000000..ec3b941
--- /dev/null
+++ b/01_Day_Introduction/Answers/01_Scripts/04_Multiple_External_Scripts/index.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Multiple External Scripts</title>
+</head>
+<body>
+    <script src="main.js"></script>
+    <script src="message.js"></script>
+</body>
+</html>
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/01_Scripts/04_Multiple_External_Scripts/main.js b/01_Day_Introduction/Answers/01_Scripts/04_Multiple_External_Scripts/main.js
new file mode 100644
index 0000000..e0b69b5
--- /dev/null
+++ b/01_Day_Introduction/Answers/01_Scripts/04_Multiple_External_Scripts/main.js
@@ -0,0 +1 @@
+console.log('This is the main script.')
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/01_Scripts/04_Multiple_External_Scripts/message.js b/01_Day_Introduction/Answers/01_Scripts/04_Multiple_External_Scripts/message.js
new file mode 100644
index 0000000..c822267
--- /dev/null
+++ b/01_Day_Introduction/Answers/01_Scripts/04_Multiple_External_Scripts/message.js
@@ -0,0 +1 @@
+console.log('This is the message script.')
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/02_Data_Types/01_Numbers/index.html b/01_Day_Introduction/Answers/02_Data_Types/01_Numbers/index.html
new file mode 100644
index 0000000..fbee9c6
--- /dev/null
+++ b/01_Day_Introduction/Answers/02_Data_Types/01_Numbers/index.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Numbers</title>
+</head>
+<body>
+    <script>
+        console.log(-1)   // Negative integer
+        console.log(0)    // Zero integer
+        console.log(1)    // Positive integer
+        console.log(-1.1) // Negative decimal
+        console.log(0.0)  // Zero decimal
+        console.log(1.0)  // Positive decimal
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/02_Data_Types/02_Strings/index.html b/01_Day_Introduction/Answers/02_Data_Types/02_Strings/index.html
new file mode 100644
index 0000000..569a29f
--- /dev/null
+++ b/01_Day_Introduction/Answers/02_Data_Types/02_Strings/index.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings</title>
+</head>
+<body>
+    <script>
+        console.log('This string is written between single quotes.') // Single quotes
+        console.log("This string is written between double quotes.") // Double quotes
+        console.log(`This string is written between backticks.`)     // Backticks
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/02_Data_Types/03_Booleans/index.html b/01_Day_Introduction/Answers/02_Data_Types/03_Booleans/index.html
new file mode 100644
index 0000000..654abde
--- /dev/null
+++ b/01_Day_Introduction/Answers/02_Data_Types/03_Booleans/index.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Booleans</title>
+</head>
+<body>
+    <script>
+        console.log(true)  // True boolean
+        console.log(false) // false boolean
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/02_Data_Types/04_Undefined/index.html b/01_Day_Introduction/Answers/02_Data_Types/04_Undefined/index.html
new file mode 100644
index 0000000..08d71bd
--- /dev/null
+++ b/01_Day_Introduction/Answers/02_Data_Types/04_Undefined/index.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Undefined</title>
+</head>
+<body>
+    <script>
+        let variable
+        console.log(variable) // It is undefined as it is not assigned to a value
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/02_Data_Types/05_Null/index.html b/01_Day_Introduction/Answers/02_Data_Types/05_Null/index.html
new file mode 100644
index 0000000..d2f8320
--- /dev/null
+++ b/01_Day_Introduction/Answers/02_Data_Types/05_Null/index.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Null</title>
+</head>
+<body>
+    <script>
+        let variable = null
+        console.log(variable) // The variable has an empty value
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/02_Data_Types/06_Checking_Data_Types/index.html b/01_Day_Introduction/Answers/02_Data_Types/06_Checking_Data_Types/index.html
new file mode 100644
index 0000000..fe64092
--- /dev/null
+++ b/01_Day_Introduction/Answers/02_Data_Types/06_Checking_Data_Types/index.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Checking Data Types</title>
+</head>
+<body>
+    <script>
+        console.log(typeof -17)
+        console.log(typeof 0)
+        console.log(typeof 29)
+        console.log(typeof -42.36)
+        console.log(typeof 0.567)
+        console.log(typeof 12.32)
+        console.log(typeof "1")
+        console.log(typeof '2')
+        console.log(typeof `3`)
+        console.log(typeof true)
+        console.log(typeof false)
+        console.log(typeof undefined)
+        console.log(typeof null) // object
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/03_Variables/index.html b/01_Day_Introduction/Answers/03_Variables/index.html
new file mode 100644
index 0000000..656e891
--- /dev/null
+++ b/01_Day_Introduction/Answers/03_Variables/index.html
@@ -0,0 +1,42 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Variables</title>
+</head>
+<body>
+    <script>
+        /*
+           The 'let' is used for changing values, while 'const' is for those
+           that are not. The let is used instead of 'var' due to leak issues.
+        */
+        // The 'camelCase' is JavaScript's variable naming convention
+        let firstName = 'Dean Harold'
+        let middleName = 'Potestades'
+        let lastName = 'Abad'
+        console.log(firstName, middleName, lastName)
+
+        const earthGravity = 9.81 // in m/s^2
+        const boilingPoint = 100  // of water in °C
+        const PI = 3.14159265359  // geometrical constant
+        console.log(earthGravity, boilingPoint, PI)
+
+        /*
+           Variables can also be declared in one line, and they are separated
+           by comma.
+        */
+        let alias = 'Dragunov',
+            age = 879,
+            race = 'Dragonkin',
+            job = 'Adventurer',
+            title = 'Dragon Lord'
+        console.log('Name:', alias)
+        console.log('Age:', age)
+        console.log('Race:', race)
+        console.log('Job:', job)
+        console.log('Title:', title)
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/04_Exercises/datatypes.js b/01_Day_Introduction/Answers/04_Exercises/datatypes.js
new file mode 100644
index 0000000..6eff904
--- /dev/null
+++ b/01_Day_Introduction/Answers/04_Exercises/datatypes.js
@@ -0,0 +1,13 @@
+console.log(typeof negativeInteger)
+console.log(typeof zeroInteger)
+console.log(typeof positiveInteger)
+console.log(typeof negativeDecimal)
+console.log(typeof zeroDecimal)
+console.log(typeof positiveDecimal)
+console.log(typeof singleQuote)
+console.log(typeof doubleQuote)
+console.log(typeof backtick)
+console.log(typeof trueBool)
+console.log(typeof falseBool)
+console.log(typeof undefinedVariable)
+console.log(typeof emptyVariable)
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/04_Exercises/index.html b/01_Day_Introduction/Answers/04_Exercises/index.html
new file mode 100644
index 0000000..3831e6d
--- /dev/null
+++ b/01_Day_Introduction/Answers/04_Exercises/index.html
@@ -0,0 +1,67 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Exercises</title>
+</head>
+<body>
+    <script>
+        // Comments can make code readable
+        // Welcome to 30DaysOfJavaScript
+        /*
+           Comments can make code readable,
+           easy to reuse and informative
+        */
+    </script>
+
+    <!--
+        Make external scripts and use the latter
+        to print the first one's variables
+    -->
+    <script src="variables.js"></script>
+    <script src="datatypes.js"></script>
+
+    <script>
+        // Declare 4 variables without assigning values
+        let a, b, c, d
+        
+        // Declare 4 variables with assigned values
+        let e = '1',
+            f = '2',
+            g = '3',
+            h = '4'
+
+        /*
+           Declare variables to store your first name,
+           last name, marital status, country, and age
+           in multiple lines.
+        */
+        let firstName = 'Dean Harold'
+        let lastName = 'Abad'
+        let maritalStatus = 'single'
+        let country = 'Philippines'
+        let age = 19
+
+        /*
+           Declare variables to store your first name,
+           last name, marital status, country, and age
+           in a single line.
+        */
+        let fn = firstName,
+            ln = lastName,
+            ms = maritalStatus,
+            ct = country,
+            ag = age
+
+        /*
+           Declare 2 variables myAge and yourAge and assign
+           them their initial values and log into the
+           browser console.
+        */
+        let myAge = 19, yourAge = 21
+        console.log("I am ", myAge, " years old.\nYou are ", yourAge, " years old.")
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/01_Day_Introduction/Answers/04_Exercises/variables.js b/01_Day_Introduction/Answers/04_Exercises/variables.js
new file mode 100644
index 0000000..30c5f30
--- /dev/null
+++ b/01_Day_Introduction/Answers/04_Exercises/variables.js
@@ -0,0 +1,13 @@
+let negativeInteger = -10
+    zeroInteger = 0,
+    positiveInteger = 42,
+    negativeDecimal = -16.84,
+    zeroDecimal = 0.0,
+    positiveDecimal = 420.69,
+    singleQuote = 'A string between single quotes',
+    doubleQuote = "A string between double quotes",
+    backtick = `A string between backticks`,
+    trueBool = true,
+    falseBool = false,
+    undefinedVariable = undefined,
+    emptyVariable = null
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/01_Data_Types/01_Primitive/index.html b/02_Day_Data_types/Answers/01_Data_Types/01_Primitive/index.html
new file mode 100644
index 0000000..5dee89a
--- /dev/null
+++ b/02_Day_Data_types/Answers/01_Data_Types/01_Primitive/index.html
@@ -0,0 +1,53 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Primitive</title>
+</head>
+<body>
+    <script>
+        /*
+           Includes:
+           Numbers - integers and floats
+           Strings - any data under single, double, or backtick quotes
+           Booleans - true or false value
+           Undefined - a declared variable without an assigned value
+           Null - an empty/no assigned value
+        */
+        // Examples of primitive data types:
+        let negativeInteger = -10
+            zeroInteger = 0,
+            positiveInteger = 42,
+            negativeDecimal = -16.84,
+            zeroDecimal = 0.0,
+            positiveDecimal = 420.69,
+            singleQuote = 'A string between single quotes',
+            doubleQuote = "A string between double quotes",
+            backtick = `A string between backticks`,
+            trueBool = true,
+            falseBool = false,
+            undefinedVariable = undefined,
+            emptyVariable = null
+        
+        // Primitive data types are immutable (non-modifiable)
+        /*
+           Here, the first letter is accessed by getting the
+           first element under the string 'singleQuote', and
+           tries to replace the capital A with its lowercase.
+        */
+        singleQuote[0] = 'a' // This would throw an error
+
+        // Comparing values will return a boolean value
+        let num1 = 10, num2 = 10
+        console.log(num1 == num2)        // true
+
+        let js = 'JavaScript', py = 'Python'
+        console.log(js == py)            // false
+
+        let lightOn = true, lightOff = false
+        console.log(lightOn == lightOff) // false
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/01_Data_Types/02_Non-Primitive/index.html b/02_Day_Data_types/Answers/01_Data_Types/02_Non-Primitive/index.html
new file mode 100644
index 0000000..c8da9ae
--- /dev/null
+++ b/02_Day_Data_types/Answers/01_Data_Types/02_Non-Primitive/index.html
@@ -0,0 +1,107 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Non-Primitive</title>
+</head>
+<body>
+    <script>
+        /*
+           Includes:
+           Objects
+           Functions
+           Arrays
+        */
+        // Array is a list of data values contained in square brackets
+        let numbers = [1, 2, 3]
+        numbers[0] = "This is the first element"
+        numbers[1] = "This is the second element"
+        numbers[2] = "This is the last element"
+
+        /*
+           Value of each index in the array are reassigned;
+           the values are changed from int to string data types.
+        */
+        console.log(numbers[0])
+        console.log(numbers[1])
+        console.log(numbers[2])
+
+        /*
+           The example proves that an array, which is a non-primitive
+           data type is mutable (modifiable).
+           Non-primitive data types are not comparable by value.
+           Even if 2 non-primitive data types have the same properties
+           and values, they are not strictly equal.
+        */
+        let set1 = [1, 2, 3],
+            set2 = [1, 2, 3]
+        console.log(set1 == set2) // false
+
+        let object1 = {
+                character: {
+                    alias: 'Dragunov',
+                    age: 879,
+                    race: 'Dragonkin',
+                    job: 'Adventurer',
+                    title: 'Dragon Lord'
+                }
+            },
+            object2 = {
+                character: {
+                    alias: 'Dragunov',
+                    age: 879,
+                    race: 'Dragonkin',
+                    job: 'Adventurer',
+                    title: 'Dragon Lord'
+                }
+            }
+        console.log(object1 == object2) // false
+
+        /*
+           We do not compare non-primitive data types; do not compare
+           objects, functions, or arrays. Their values are referred to
+           as 'reference' types, because they are being compared by
+           reference instead of values.
+           Two objects are only strictly equal if they refer to the
+           same underlying object.
+
+           So instead of the following:
+           let numbers1 = [1, 2, 3],
+               numbers2 = [1, 2, 3]
+           console.log(numbers1 == numbers2) // false
+
+           let character1 = {
+                   alias: 'Dragunov',
+                   age: 879,
+                   race: 'Dragonkin',
+                   job: 'Adventurer',
+                   title: 'Dragon Lord'
+               },
+               character2 = {
+                   alias: 'Dragunov',
+                   age: 879,
+                   race: 'Dragonkin',
+                   job: 'Adventurer',
+                   title: 'Dragon Lord'
+               }
+           console.log(character1 == character2) // false
+        */
+        // We do:
+        let numbers1 = [1, 2, 3],
+            numbers2 = numbers1
+        console.log(numbers1 == numbers2) // true
+
+        let character1 = {
+                alias: 'Dragunov',
+                age: 879,
+                race: 'Dragonkin',
+                job: 'Adventurer',
+                title: 'Dragon Lord'
+            },
+            character2 = character1
+        console.log(character1 == character2) // true
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/02_Numbers/01_Declaring_Number_Data_Types/index.html b/02_Day_Data_types/Answers/02_Numbers/01_Declaring_Number_Data_Types/index.html
new file mode 100644
index 0000000..0de41cf
--- /dev/null
+++ b/02_Day_Data_types/Answers/02_Numbers/01_Declaring_Number_Data_Types/index.html
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Numbers: Declaring Number Data Types</title>
+</head>
+<body>
+    <script>
+        // Examples of integers and decimals
+        let negativeInteger = -10
+            zeroInteger = 0,
+            positiveInteger = 42,
+            negativeDecimal = -16.84,
+            zeroDecimal = 0.0,
+            positiveDecimal = 420.69
+
+        // Some real-world constants
+        const earthGravity = 9.81  // in m/s^2
+              boilingPoint = 100,  // of water in °C
+              bodyTemperature = 37 // of humans in °C
+              PI = 3.14159265359   // geometrical constant
+        
+        console.log(earthGravity, boilingPoint, bodyTemperature, PI)
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/02_Numbers/02_Math_Object/index.html b/02_Day_Data_types/Answers/02_Numbers/02_Math_Object/index.html
new file mode 100644
index 0000000..a13e732
--- /dev/null
+++ b/02_Day_Data_types/Answers/02_Numbers/02_Math_Object/index.html
@@ -0,0 +1,61 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Numbers: Math Object</title>
+</head>
+<body>
+    <script>
+        // Some real-world constants
+        const earthGravity = 9.81                             // in m/s^2
+              boilingPoint = 100,                             // of water in °C
+              bodyTemperature = 37                            // of humans in °C
+        
+        // The Math Object provides a lots of methods to work with numbers
+        const PI = Math.PI                                    // geometrical constant
+        console.log(PI)                                       // 3.141592653589793
+        
+        /*
+           Round off to the closest number; if above 0.5, round up, else if
+           below 0.5, round down.
+        */
+        console.log(Math.round(PI))                           // round off, 3
+        console.log(Math.round(earthGravity))                 // round off, 10
+        console.log(Math.floor(PI))                           // round down, 3
+        console.log(Math.ceil(PI))                            // round up, 4
+        console.log(Math.min(-0.4, 9, -20.45))                // lowest, -20.45
+        console.log(Math.max(-0.4, 9, -20.45))                // highest, 9
+
+        // Create random float from 0 to 0.999999
+        const random_float = Math.random()                    // random float
+        console.log(random_float)
+
+        // Create random integer from 0 to 10
+        const random_integer = Math.floor(Math.random() * 11) // random integer
+        console.log(random_integer)
+
+        // Absolute value
+        console.log(Math.abs(-99))                            // 99
+
+        // Square root
+        console.log(Math.sqrt(25))                            // 5
+        console.log(Math.sqrt(2))                             // 1.4142135623730951
+
+        // Power
+        console.log(Math.pow(2, 5))                           // 32
+        console.log(Math.E)                                   // 2.718281828459045
+
+        // Logarithm - returns the natural logarithm with base E of x, Math.log(x)
+        console.log(Math.log(2))                              // 0.6931471805599453
+        console.log(Math.log(10))                             // 2.302585092994046
+
+        // Trigonometry
+        console.log(Math.sin(0))                              // 0
+        console.log(Math.sin(90))                             // 0.8939966636005579
+        console.log(Math.cos(0))                              // 1
+        console.log(Math.cos(90))                             // -0.4480736161291702
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/02_Numbers/03_Random_Number_Generator/index.html b/02_Day_Data_types/Answers/02_Numbers/03_Random_Number_Generator/index.html
new file mode 100644
index 0000000..1b5a147
--- /dev/null
+++ b/02_Day_Data_types/Answers/02_Numbers/03_Random_Number_Generator/index.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Numbers: Random Number Generator</title>
+</head>
+<body>
+    <script>
+        // Create random float from 0 to 0.999999
+        let random_float = Math.random()                    // random float
+        console.log(random_float)
+
+        // Create random number from 0 to 10.99
+        let random_number = random_float * 11               // random number
+
+        // Create random integer from 0 to 10
+        let random_integer = Math.floor(random_number)      // random integer
+        console.log(random_integer)
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/01_Types/index.html b/02_Day_Data_types/Answers/03_Strings/01_Types/index.html
new file mode 100644
index 0000000..22cb099
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/01_Types/index.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Types</title>
+</head>
+<body>
+    <script>
+        // Various strings under single, double, and backtick quotes
+        let space = ' ',
+            // Examples:
+            single = 'string under single quote',
+            double = "string under double quote",
+            backtick = `string under backtick quote`,
+            singleInDouble = "string with single quote under a 'double quote'",
+            singleInBacktick = `string with single quote under a 'backtick quote'`
+        console.log(single)
+        console.log(double)
+        console.log(backtick)
+        console.log(singleInDouble)
+        console.log(singleInBacktick)
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/02_Concatenation/index.html b/02_Day_Data_types/Answers/03_Strings/02_Concatenation/index.html
new file mode 100644
index 0000000..827a84e
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/02_Concatenation/index.html
@@ -0,0 +1,113 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Concatenation</title>
+</head>
+<body>
+    <script>
+        /*
+           Concatenation - connecting 2 or more strings together
+           There are multiple ways to concatenate strings
+        */
+        // Using addition operators:
+        let space = ' ',
+            // Examples:
+            firstName = 'Dean Harold',
+            middleName = 'Potestades',
+            lastName = 'Abad',
+            maritalStatus = 'single',
+            country = 'Philippines',
+            age = 19
+
+            fullName = firstName + space + middleName + space + lastName,
+            fullInfo = 'Hi, I am ' + fullName + '. Currently I am ' + age + ' years old and ' + maritalStatus + '. I live in the ' + country + '.'
+        console.log(fullInfo)
+
+        /*
+           Long Literal Strings - backslash character (\) is
+           used at the end of each line to indicate that the
+           string will continue on the next line as the text
+           is too big to be written in a single line:
+        */
+        const paragraph = "Hi, I am Dean Harold Potestades Abad. Currently I am 19 years old and single. I live in the Philippines. \
+I like drawing and designing characters, animating things, and coding simple programs. \
+I spend most of my time on computer due to being a Computer Science student. \
+I have no school projects at the moment."
+        console.log(paragraph)
+
+        /*
+           Escape Sequences in Strings - the backslash (\)
+           character followed by other characters is an
+           escape sequence.
+
+           The most commonly used escape characters:
+           \n - new line
+           \t - Tab or 8 spaces
+           \\ - backslash
+           \' - single quote
+           \" - double quote
+        */
+        // Line break or new line
+        console.log('This is such a great learning material to learn JavaScript.\nI would recommend this resource in various platforms.')
+        
+        // Tab
+        console.log('Name of Resource\tType of Resource\tLanguage')
+        console.log('30DaysOfJavaScript\tLearning Resource\tJavaScript')
+        
+        // To be able to write backslash in a string
+        console.log('The \\ character is called backslash symbol.')
+
+        // To be able to write single quotes in a string
+        console.log("The \'single quotes\' in string are possible with the use of \\ character.")
+
+        // To be able to write double quotes in a string
+        console.log('The \"double quotes\" in string are possible with the use of \\ character.')
+        
+        // Mixture of \n, \', and \"'
+        console.log('I don\'t prefer using the \'shortcutted\' word \'don\'t\' in my examples,\nbut the 2 words \"do\" and \"not.\"')
+        
+        /*
+           Template Literals - 2 backticks are used in this
+           method. Data can be 'injected' as expressions in
+           this template string.
+           To inject data, we enclose the expression with a
+           curly bracket ({}), preceded by a $ sign.
+
+           Syntax:
+           `String literal text ${expression}`
+        */
+        let a = 1, b = 2
+        // The data is injected dynamically
+        console.log(`The value of a is ${a} and b is ${b}.\nTogether their sum is ${a + b}.`)
+
+        /*
+           Another example from the previously used variables
+           earlier i.e. the following:
+
+           let space = ' ',
+               firstName = 'Dean Harold',
+               middleName = 'Potestades',
+               lastName = 'Abad',
+               maritalStatus = 'single',
+               country = 'Philippines',
+               age = 19
+
+           fullName = firstName + space + middleName + space + lastName,
+           fullInfo = `Hi, I am ${fullName}. Currently I am ${age} years old and ${maritalStatus}. I live in the ${country}.`
+        */
+        fullInfo = `Hi, I am ${fullName}. Currently I am ${age} years old and ${maritalStatus}. I live in the ${country}.`
+        console.log(fullInfo)
+
+        /*
+           Using a string template or string interpolation
+           method, we can add expressions which could be a
+           value, or use make comparisons, arithmetic ope-
+           rations, and ternary operation.
+        */
+        console.log(`${a} is greater than ${b}: ${a > b}`) // 1 is greater than 2: false
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/03_Methods/01_length/index.html b/02_Day_Data_types/Answers/03_Strings/03_Methods/01_length/index.html
new file mode 100644
index 0000000..b1eb4a6
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/03_Methods/01_length/index.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Methods - Length</title>
+</head>
+<body>
+    <script>
+        // length - returns the number of characters in a string
+        let js = 'JavaScript'
+        let py = 'Python'
+        console.log(js.length) // 10
+        console.log(py.length) // 6
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/03_Methods/02_Accessing_Characters_in_String/index.html b/02_Day_Data_types/Answers/03_Strings/03_Methods/02_Accessing_Characters_in_String/index.html
new file mode 100644
index 0000000..4dc9f06
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/03_Methods/02_Accessing_Characters_in_String/index.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Methods - Accessing Characters in String</title>
+</head>
+<body>
+    <script>
+        // string[index] - access a character in a string by its index
+        let js = 'JavaScript',
+            firstLetter = js[0],
+            finalPosition = js.length - 1,
+            lastLetter = js[finalPosition] // Decrease by 1 its length as index starts with 0 when counting
+        console.log(`Name: ${js}\nFirst letter: ${firstLetter}\nLast letter: ${lastLetter}`)
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/03_Methods/03_toUpperCase()/index.html b/02_Day_Data_types/Answers/03_Strings/03_Methods/03_toUpperCase()/index.html
new file mode 100644
index 0000000..e7d84b0
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/03_Methods/03_toUpperCase()/index.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Methods - toUpperCase()</title>
+</head>
+<body>
+    <script>
+        // toUpperCase() - changes the string to uppercase letters
+        let js = 'JavaScript'
+        console.log(js.toUpperCase()) // JAVASCRIPT
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/03_Methods/04_toLowerCase()/index.html b/02_Day_Data_types/Answers/03_Strings/03_Methods/04_toLowerCase()/index.html
new file mode 100644
index 0000000..19bfba3
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/03_Methods/04_toLowerCase()/index.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Methods - toLowerCase()</title>
+</head>
+<body>
+    <script>
+        // toLowerCase() - changes the string to lowercase letters
+        let js = 'JavaScript'
+        console.log(js.toLowerCase()) // javascript
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/03_Methods/05_substr()_and_substring()/index.html b/02_Day_Data_types/Answers/03_Strings/03_Methods/05_substr()_and_substring()/index.html
new file mode 100644
index 0000000..69657fa
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/03_Methods/05_substr()_and_substring()/index.html
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Methods - substr() and substring()</title>
+</head>
+<body>
+    <script>
+        /*
+           substr() - has 2 arguments, the starting index and
+           the number of characters to slice
+        */
+        let js = 'JavaScript'
+        console.log(js.substr(0, 4))     // Java
+        console.log(js.substr(4, 6))     // Script
+
+        /*
+           substring() - has 2 arguments, the starting index and
+           the stopping index, and it does not include the stop-
+           ping index's character
+        */
+        console.log(js.substring(0, 4))  // Java
+        console.log(js.substring(4, 10)) // Script
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/03_Methods/06_split()/index.html b/02_Day_Data_types/Answers/03_Strings/03_Methods/06_split()/index.html
new file mode 100644
index 0000000..1e4531e
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/03_Methods/06_split()/index.html
@@ -0,0 +1,34 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Methods - split()</title>
+</head>
+<body>
+    <script>
+        /*
+           split() - splits a string at a specified place, and it changes
+           the string into an array of parts from the splitting based from
+           the passed argument
+        */
+        let title = '30 Days of JavaScript'
+        // Simply changes into an array
+        console.log(title.split())      // ["30 Days of JavaScript"]
+
+        // Changes into array of words as space or ' ' is the point of split
+        console.log(title.split(' '))   // ["30", "Days", "of", "JavaScript"]
+
+        let name = 'Dean'
+        // Changes into array of letters due to each next '' point
+        console.log(name.split('')) // ["D", "e", "a", "n"]
+
+        let drinks = 'Milo, Coca-Cola, and Delight'
+        // Removes the commas only, therefore retaining the spaces
+        console.log(drinks.split(','))   // ["Milo", " Coca-Cola", " and Delight"]
+        // Removes both commas and spaces, therefore leaving only the nouns
+        console.log(drinks.split(', '))  // ["Milo", "Coca-Cola", "and Delight"]
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/03_Methods/07_trim()/index.html b/02_Day_Data_types/Answers/03_Strings/03_Methods/07_trim()/index.html
new file mode 100644
index 0000000..1e81f44
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/03_Methods/07_trim()/index.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Methods - trim()</title>
+</head>
+<body>
+    <script>
+        /*
+           trim() - removes trailing space in the beginning or the end
+           of a string
+        */
+        let js = '           JavaScript           ',
+            title = '    30 Days of JavaScript    '
+        console.log(js.trim(' ')) // JavaScript
+        console.log(title.trim()) // 30 Days of JavaScript
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/03_Methods/08_includes()/index.html b/02_Day_Data_types/Answers/03_Strings/03_Methods/08_includes()/index.html
new file mode 100644
index 0000000..8d99a3f
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/03_Methods/08_includes()/index.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Methods - includes()</title>
+</head>
+<body>
+    <script>
+        /*
+           includes() - takes a substring argument and checks if it is
+           in a string, and it returns a boolean value
+        */
+        let title = '30 Days of JavaScript'
+        console.log(title.includes('30'))   // true
+        console.log(title.includes('69'))   // false
+        console.log(title.includes('Days')) // true
+        console.log(title.includes('days')) // false
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/03_Methods/09_replace()/index.html b/02_Day_Data_types/Answers/03_Strings/03_Methods/09_replace()/index.html
new file mode 100644
index 0000000..0da8af0
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/03_Methods/09_replace()/index.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Methods - replace()</title>
+</head>
+<body>
+    <script>
+        /*
+           replace() - takes 2 parameters the old substring and new one
+        */
+        let title = '30 Days of Python'
+        console.log(title.replace('Python', 'JavaScript')) // 30 Days of JavaScript
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/03_Methods/10_charAt()/index.html b/02_Day_Data_types/Answers/03_Strings/03_Methods/10_charAt()/index.html
new file mode 100644
index 0000000..e7d5e35
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/03_Methods/10_charAt()/index.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Methods - charAt()</title>
+</head>
+<body>
+    <script>
+        /*
+           charAt() - takes index in a string and returns its value
+        */
+        let title = '30 Days of JavaScript',
+            count = title.length
+        console.log(title.charAt(0))         // 3
+        console.log(title.charAt(count - 1)) // n
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/03_Methods/11_charCodeAt()/index.html b/02_Day_Data_types/Answers/03_Strings/03_Methods/11_charCodeAt()/index.html
new file mode 100644
index 0000000..2f2a595
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/03_Methods/11_charCodeAt()/index.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Methods - charCodeAt()</title>
+</head>
+<body>
+    <script>
+        /*
+           charCodeAt() - takes index in a string and returns its char
+           code or ASCII value
+        */
+        let title = '30 Days of JavaScript',
+            count = title.length
+        console.log(title.charCodeAt(0))         // 51
+        console.log(title.charCodeAt(count - 1)) // 110
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/02_Day_Data_types/Answers/03_Strings/03_Methods/12_indexOf()/index.html b/02_Day_Data_types/Answers/03_Strings/03_Methods/12_indexOf()/index.html
new file mode 100644
index 0000000..c438fec
--- /dev/null
+++ b/02_Day_Data_types/Answers/03_Strings/03_Methods/12_indexOf()/index.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>30DaysOfJavaScript: Data Types - Strings: Methods - indexOf()</title>
+</head>
+<body>
+    <script>
+        /*
+           indexOf() - takes a substring and if it exists, it will
+           return the first position of the substring, and if it
+           does not exist it will return -1
+        */
+        let title = '30 Days of JavaScript',
+            count = title.length
+        console.log(title.indexOf('Days'))       // 3
+        console.log(title.indexOf('JavaScript')) // 11
+    </script>
+</body>
+</html>
\ No newline at end of file