5. *substr()*: It takes two arguments,the starting index and number of characters to slice.
5. *substr()*: It takes two arguments,the starting index and number of characters to slice.
```js
let string = 'JavaScript'
@ -999,7 +1000,7 @@ let country = 'Finland'
console.log(country.substr(3, 4)) // land
```
6. *substring()*: It takes two arguments,the starting index and the stopping index but it doesn't include the stopping index.
6. *substring()*: It takes two arguments,the starting index and the stopping index but it doesn't include the stopping index.
```js
let string = 'JavaScript'
@ -1093,6 +1094,7 @@ console.log(string.charAt(lastIndex)) // t
```js
string.charCodeAt(index)
```
```js
let string = '30 Days Of JavaScript'
console.log(string.charCodeAt(3)) // D ASCII number is 51
@ -1100,6 +1102,7 @@ let lastIndex = string.length - 1
console.log(string.charCodeAt(lastIndex)) // t ASCII is 116
```
13. *indexOf()*: Takes takes a substring and if the substring exists in a string it returns the first position of the substring if does not exist it returns -1
```js
@ -1552,7 +1555,7 @@ I would like to recommend you to read about operator precendence from this [link
As you have seen at very beginning alert() method displays an alert box with a specified message and an OK button. It is a builtin method and it takes on argument.
```js
alert(mesage)
alert(message)
```
```js
@ -1581,10 +1584,12 @@ A confirm box is often used to ask permission from a user to do something. Windo
Clicking the OK yields true value, clicking the Cancel yields true value.
```js
const agree = confirm('Do you like to delete ? ')
console.log(agree)
const agree = confirm('Are you sure you like to delete? ')
console.log(agree) // result will be true or false based on what you click on the dialog box
```
These are not all the window methods we will have a separate section to go deep into window methods.
## Date Object
Time is an important thing. We like to know the time a certain activity or event. In JavaScript current time and date is created using JavaScript Date Object. The object we create using Date object provides many methods to work with date and time.The methods we use to get date and time information from a date object values are started with a word _get_ because it provide the information.
@ -1627,7 +1632,17 @@ Let's extract or get the date of the month from a time object.
```js
const now = new Date ()
console.log(now.getMonth()) // 0, because the month is January, month(0-11)
console.log(now.getDate()) // 4, because the day of the month is 4th, day(0-31)
```
### Getting day
Let's extract or get the day of the week from a time object.
```js
const now = new Date ()
console.log(now.getDay()) // 6, because the day is Saturday which is the 5th day,
// Getting the weekday as a number (0-6)
```
### Getting hours
@ -1653,7 +1668,7 @@ console.log(now.getMinutes()) // 56, because the time is 00:56:41
Let's extract or get the seconds from a time object.
```js
const now = new Date () //
const now = new Date ()
console.log(now.getSeconds()) // 41, because the time is 00:56:41
```
@ -1668,7 +1683,7 @@ const now = new Date () //
console.log(now.getTime()) // 1578092201341, this is the number of seconds passed from January 1, 1970 to January 4, 2020 00:56:41
```
2. Using *Date.now()*
1. Using *Date.now()*
```js
const allSeconds = Date.now () //
@ -1750,7 +1765,7 @@ Figure out the result of the following expressions first without using console.l
## 6 Ternary Operator
1. If the length of your name is greater than 7 say, your name is long else say your name is short.
2. Compare your first name length and your family name length and you should get this output.
1. Compare your first name length and your family name length and you should get this output.
```js
let firstName = 'Asabeneh'
@ -1762,7 +1777,7 @@ let lastName = 'Yetayeh
Your first name, Asabeneh is longer than your family name, Yetayeh
```
3. Declare two variables _myAge_ and _yourAge_ and assign them initial values and myAge and yourAge.
1. Declare two variables _myAge_ and _yourAge_ and assign them initial values and myAge and yourAge.
Output:
```js
@ -1775,7 +1790,7 @@ Your first name, Asabeneh is longer than your family name, Yetayeh
I am 225 years older than you.
```
4. Using prompt get the year the user was born and if the user is 18 or above allow the user to drive if not tell the user to wait a certain amount of years.
1. Using prompt get the year the user was born and if the user is 18 or above allow the user to drive if not tell the user to wait a certain amount of years.
```js
// if the age is 25
@ -1787,9 +1802,9 @@ You are 25. You are old enough to drive
## 7. Exercises: Date time Object
1. What is the year today?
1. What is the month today?
1. What is the month today as a number?
1. What is the date today?
1. What is the day today?
1. What is the day today as a number?
1. What is the hours now?
1. What is the minutes now?
1. Find out the numbers of seconds elapsed from January 1, 1970 to now.
Asabeneh
5 years ago