diff --git a/01_Day_JavaScript_Refresher/arrays/README.md b/01_Day_JavaScript_Refresher/arrays/README.md
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+#trabajando con arrays en JavaScript
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diff --git a/01_Day_JavaScript_Refresher/arrays/array-methods.js b/01_Day_JavaScript_Refresher/arrays/array-methods.js
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+// These are some of the available methods to deal with arrays:
+
+// printing title, result of the method, print an empty line
+
+function print(title, results){
+    console.log("\n **********************" + title + "*********************\n")
+    results.forEach(element => {
+        console.log(element)
+    });
+    console.log('\n#######################END########################\n\n\n')
+}
+
+
+// Array
+const arr = Array()
+print('Empty Array', ['array = ' + arr])
+
+
+// length
+const arrayLenght1 = Array(2)
+const arrayLenght2 = [1,2,3]
+print('length', [
+    'array1 = ' + arrayLenght1, 
+    'array1 Length = ' + arrayLenght1.length,
+    'array2 = ' + arrayLenght2,
+    'array2 Length = ' + arrayLenght2.length
+])
+
+
+// concat
+const arrayConcat1 = [1,2,3]
+const arrayConcat2 = [4, 5, 6]
+const concat = arrayConcat1.concat(arrayConcat2)
+print('concat', [
+    'array = ' + arrayConcat1,
+    'array = ' + arrayConcat2,
+    'concat = ' + concat
+])
+
+
+// indexOf
+const arrayIndexOf = [1,2,3,4,5]
+print('indexOf', [
+    'array = ' + arrayIndexOf,
+    'array.indexOf(5) = ' + arrayIndexOf.indexOf(5),
+    'array.indexOf(5) = ' + arrayIndexOf.indexOf(0),
+    'array.indexOf(5) = ' + arrayIndexOf.indexOf(1),
+    'array.indexOf(5) = ' + arrayIndexOf.indexOf(6),
+])
+
+
+// // slice
+// console.log('slice')
+
+
+
+// // splice
+// console.log('splice')
+
+
+
+// // join
+// console.log('join')
+
+
+// toString
+const arrayToString = [1,2,3,4,5]
+print('toString', [
+    'array filled with numbers = ' + arrayToString,
+    'array.toString() = ' + arrayToString.toString()
+])
+// console.log('toString')
+
+
+// // includes
+const includeNumbers = [1, 2, 3, 4, 5]
+const includeWebTechs = [
+  'HTML',
+  'CSS',
+  'JavaScript',
+  'React',
+  'Redux',
+  'Node',
+  'MongoDB',
+] // List of web technologies
+print('includes', [
+    'array = ' + includeNumbers,
+    'includeNumbers(5) ? ' + includeNumbers.includes(5),
+    'includeNumbers(0) ? ' + includeNumbers.includes(0),
+    'includeNumbers(1) ? ' + includeNumbers.includes(1),
+    'includeNumbers(6) ? ' + includeNumbers.includes(6),
+    '\n',
+    'WebTechs = ' + includeWebTechs,
+    'include(node) ? = ' + includeWebTechs.includes('Node'),
+    'include(C) ? = ' + includeWebTechs.includes('C'),
+])
+
+// lastIndexOf
+const arraylastIndexOf = [1,2,3,4,5,3,1,2]
+print('lastIndexOf', [
+    'array = ' + arraylastIndexOf,
+    'array.lastIndexOf(2) = ' + arraylastIndexOf.lastIndexOf(2),
+    'array.lastIndexOf(0) = ' + arraylastIndexOf.lastIndexOf(0),
+    'array.lastIndexOf(1) = ' + arraylastIndexOf.lastIndexOf(1),
+    'array.lastIndexOf(4) = ' + arraylastIndexOf.lastIndexOf(4),
+    'array.lastIndexOf(6) = ' + arraylastIndexOf.lastIndexOf(6)
+])
+
+// // isArray
+const numbersisArray1 = [1, 2, 3, 4, 5]
+const variable = 100
+print('isArray',[
+    'array1 = ' + numbersisArray1,
+    'Array.isArray(numbersisArray1) ? ' + Array.isArray(numbersisArray1),
+    'variable = ' + variable,
+    'Array.isArray(variable) ? ' + Array.isArray(variable)
+])
+
+
+// // fill
+
+// console.log('fill')
+
+
+// // push
+// console.log('push')
+
+// // pop
+// console.log('pop')
+
+// // shift
+// console.log('shift')
+
+// // unshift
+// console.log('unshift')
+
+
+
diff --git a/01_Day_JavaScript_Refresher/arrays/excercise1.js b/01_Day_JavaScript_Refresher/arrays/excercise1.js
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+// Exercise: Level 1
+
+const countries = [
+    'Albania',
+    'Bolivia',
+    'Canada',
+    'Denmark',
+    'Ethiopia',
+    'Finland',
+    'Germany',
+    'Hungary',
+    'Ireland',
+    'Japan',
+    'Kenya',
+]
+
+const webTechs = [
+    'HTML',
+    'CSS',
+    'JavaScript',
+    'React',
+    'Redux',
+    'Node',
+    'MongoDB',
+]
+
+// Declare an empty array;
+const task1 = Array()
+
+
+// Declare an array with more than 5 number of elements
+const task2 = [1, 2, 3, 4]
+
+// Find the length of your array
+const task3 = task2.length
+// console.log(task3)
+
+// Get the first item, the middle item and the last item of the array
+const task4Firt = task2[0]
+const task4Middle = task2[(Math.round(task3 - 1) / 2, 2)]
+const task4Last = task2[task3 - 1]
+// console.log(`
+//     First Item:  ${task4Firt}
+//     Middle Item: ${task4Middle}
+//     Last Item: ${task4Last}
+// `)
+
+// Declare an array called mixedDataTypes, put different data types in the array and find the length of the array. 
+// The array size should be greater than 5
+const mixedDataTypes = ['string', 'c', 1, false, { name: 'nico', favfood: 'pasta' }]
+// console.log(`
+//     mixedDataTypes = ${mixedDataTypes}
+//     mixedDataTypes.length = ${mixedDataTypes.length}
+// `)
+
+
+// Declare an array variable name itCompanies and assign initial values Facebook, Google, Microsoft, Apple, IBM, Oracle and Amazon
+const itCompanies = ['Facebook', 'Google', 'Microsoft', 'Apple', 'IBM', 'Oracle', 'Amazon']
+
+// Print the array using console.log()
+// console.log(itCompanies)
+
+// Print the number of companies in the array
+
+// console.log(`Numbe of companies = ${itCompanies.length}`)
+// Print the first company, middle and last company
+
+// console.log(`
+//     first ${itCompanies[0]}
+//     middle ${itCompanies[(Math.round((itCompanies.length - 1) / 2, 2))]}
+//     last ${itCompanies.length - 1}
+// `)
+
+// Print out each company
+// console.log(itCompanies)
+
+// Change each company name to uppercase one by one and print them out
+// itCompanies[0] = 'FACEBOOK'
+// itCompanies[1] = 'GOOGLE'
+// itCompanies[2] = 'MICROSOFT'
+// itCompanies[3] = 'APPLE'
+// itCompanies[4] = 'IBM'
+// itCompanies[5] = 'ORACLE'
+// itCompanies[6] = 'AMAZON'
+// console.log(itCompanies)
+
+// Print the array like as a sentence: Facebook, Google, Microsoft, Apple, IBM,Oracle and Amazon are big IT companies.
+// console.log(`
+//     ${itCompanies.slice(0,itCompanies.length-1)} and ${itCompanies[itCompanies.length-1]} are big IT companies.
+// `)
+
+// Check if a certain company exists in the itCompanies array. If it exist return the company else return a company is not found
+const companyToSearch1 = 'SiteHost'
+const companyToSearch2 = 'Amazon'
+const results1 = itCompanies.includes(companyToSearch1)
+const results2 = itCompanies.includes(companyToSearch2)
+
+// console.log(`
+//     SiteHost ? = ${results1}
+//     Amazon ? = ${results2}
+// `)
+
+// Filter out companies which have more than one 'o' without the filter method
+
+
+// Sort the array using sort() method
+const arrSorted = itCompanies.sort()
+// console.log(`arrSorted = ${arrSorted}`)
+
+
+// Reverse the array using reverse() method
+const arrReverse = arrSorted.reverse()
+console.log(`arrReverse = ${arrReverse}`)
+
+
+// Slice out the first 3 companies from the array
+console.log(arrReverse.slice(3))
+
+// Slice out the last 3 companies from the array
+console.log(arrReverse.slice(0,3))
+
+// Slice out the middle IT company or companies from the array
+
+
+// Remove the first IT company from the array
+console.log(`
+    arrReverse.shift() = ${arrReverse.shift()}
+    arrReverse = ${arrReverse}
+`)
+
+// Remove the middle IT company or companies from the array
+
+// Remove the last IT company from the array
+console.log(`
+    arrReverse.pop() = ${arrReverse.pop()}
+    arrReverse = ${arrReverse}
+`)
+
+
+// Remove all IT companies
+// arrReverse = ['']
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diff --git a/01_Day_JavaScript_Refresher/arrays/excercise2/countries.js b/01_Day_JavaScript_Refresher/arrays/excercise2/countries.js
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+const countries = [
+    'Albania',
+    'Bolivia',
+    'Canada',
+    'Denmark',
+    'Ethiopia',
+    'Finland',
+    'Germany',
+    'Hungary',
+    'Ireland',
+    'Japan',
+    'Kenya',
+]
+
+exports.countries = countries
diff --git a/01_Day_JavaScript_Refresher/arrays/excercise2/main.js b/01_Day_JavaScript_Refresher/arrays/excercise2/main.js
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+// 1. Create a separate countries.js file and store the countries array into this file, create a separate file web_techs.js and store the webTechs array into this file. Access both file in main.js file
+
+
+const { countries } = require('./countries');
+const { webTechs } = require('./web_Techs');
+
+// 2. First remove all the punctuations and change the string to array and count the number of words in the array
+let text = 'I love teaching and empowering people I teach HTML CSS JS React, Python'
+
+text = text.split(' ')
+// console.log(text)
+// console.log(text.length)
+
+
+
+// 3. In the following shopping cart add, remove, edit items
+
+const shoppingCart = ['Milk', 'Coffe', 'Tea', 'Honey']
+
+if (shoppingCart[0] !== 'Meat') {
+    shoppingCart.unshift('Meat')
+}
+if (shoppingCart[0] !== 'Sugar') {
+    shoppingCart.push('Sugar')
+}
+
+const indexHoney = shoppingCart.indexOf('Honey')
+shoppingCart.splice(indexHoney, 1)
+
+const indexTea = shoppingCart.indexOf('Tea')
+shoppingCart[indexTea] = 'Green Tea'
+
+// console.log(shoppingCart)
+
+
+
+// 4. In countries array check if 'Ethiopia' exists in the array if it exists print 'ETHIOPIA'. If it does not exist add to the countries list.
+// console.log(countries)
+
+if (countries.indexOf('Ethiopia')) {
+    // console.log('ETHIOPIA')
+} else {
+    countries.push('ETHIOPIA')
+}
+
+
+
+// 5. In the webTechs array check if Sass exists in the array and if it exists print 'Sass is a CSS preprocess'. If it does not exist add Sass to the array and print the array.
+if (webTechs.indexOf('Sass')) {
+    // console.log('Sass is a CSS preprocess')
+} else {
+    webTechs.push('Sass')
+}
+
+
+// 6. Concatenate the following two variables and store it in a fullStack variable.
+
+const frontEnd = ['HTML', 'CSS', 'JS', 'React', 'Redux']
+const backEnd = ['Node', 'Express', 'MongoDB']
+const fullStack = frontEnd.concat(backEnd)
+
+console.log(fullStack)
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diff --git a/01_Day_JavaScript_Refresher/arrays/excercise2/web_techs.js b/01_Day_JavaScript_Refresher/arrays/excercise2/web_techs.js
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+++ b/01_Day_JavaScript_Refresher/arrays/excercise2/web_techs.js
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+const webTechs = [
+    'HTML',
+    'CSS',
+    'JavaScript',
+    'React',
+    'Redux',
+    'Node',
+    'MongoDB',
+]
+
+exports.webTechs = webTechs
diff --git a/01_Day_JavaScript_Refresher/arrays/excercise3/excercise3.js b/01_Day_JavaScript_Refresher/arrays/excercise3/excercise3.js
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+++ b/01_Day_JavaScript_Refresher/arrays/excercise3/excercise3.js
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+// Exercise: Level 3
+
+// The following is an array of 10 students ages: js const ages = [19, 22, 19, 24, 20, 25, 26, 24, 25, 24]  - Sort the array and find the min and max age - Find the median age(one middle item or two middle items divided by two) - Find the average age(all items divided by number of items) - Find the range of the ages(max minus min) - Compare the value of (min - average) and (max - average), use abs() method
+// 1.Slice the first ten countries from the countries array
+
+const ages = [19, 22, 19, 24, 20, 25, 26, 24, 25, 24]
+
+/* 
+    Required:
+    - sort the Age array
+    - find the min and max age
+    - find the median age (one middle item or two middle items divided by two)
+    - find the avg age (all items divided by numbers of items)
+    - range of ages (max - min)
+    - Compare values (Min - Avg)
+    - Compare values (max - avg)
+    - MUST use abd() for the values.
+*/
+ages.sort()
+const length = ages.length
+const isEven = length % 2 === 0 ? true : false
+const min = ages[0]
+const max = ages[length - 1]
+let medianAge
+function sumArray(arr) {
+    return arr.reduce((total, currentValue) => total + currentValue);
+}
+let avg = sumArray(ages) / length
+const rangeOfAges = Math.abs(max - min)
+const comparingMinAvg = (Math.abs(min - avg)).toFixed(2)
+const comparingMaxAvg = (Math.abs(max - avg)).toFixed(2)
+
+if (isEven) {
+    const index1 = Math.round(length / 2, 2)
+    const index2 = index1 + 1
+    medianAge = (ages[index1] + ages[index2]) / 2
+
+} else {
+    const index1 = (length - 1) / 2
+    console.log('index = ' + index1)
+    medianAge = ages[index1] / 2
+}
+
+
+
+console.log(`
+    Array Sorted = ${ages}
+    length = ${length}
+    is the array even? ${isEven}
+    min = ${min}
+    max = ${max}
+    median age = ${medianAge} 
+    Average age = ${avg}
+    range of ages = ${rangeOfAges}
+    Values to compare (min - Avg) = ${comparingMinAvg}
+    Values to compare (max - Avg) =  ${comparingMaxAvg}
+`)
+
+
+
+
+
+
+
+