corrections

Author: Asabeneh

03_Day_Booleans_operators_date/03_booleans_operators_date.md

@@ -73,7 +73,7 @@ We agreed that boolean values are either true or false.
 ### Truthy values
 
 - All numbers(positive and negative) are truthy except zero
-- All strings are truthy
+- All strings are truthy except an empty string ('')
 - The boolean true
 
 ### Falsy values
@@ -616,7 +616,7 @@ console.log(`${date}/${month}/${year} ${hours}:${minutes}`) // 4/1/2020 0:56
 1. Write a script that prompt the user to enter number of years. Calculate the number of seconds a person can live. Assume some one lives just hundred years
 
    ```sh
-   Enter number of yours you live: 100
+   Enter number of years you live: 100
    You lived 3153600000 seconds.
    ```
 

06_Day_Loops/06_day_loops.md

@@ -108,7 +108,7 @@ const numbers = [1, 2, 3, 4, 5]
 const newArr = []
 let sum = 0
 for(let i = 0; i < numbers.length; i++){
-  newArr.push(i * i)
+  newArr.push( numbers[i] ** 2)
 
 }
 
@@ -406,6 +406,7 @@ for(let i = 0; i <= 5; i++){
       ['Germany', 'GER', 7],
       ['Hungary', 'HUN', 7],
       ['Ireland', 'IRE', 7],
+      ['Iceland', 'ICE', 7],
       ['Japan', 'JAP', 5],
       ['Kenya', 'KEN', 5]
     ]
@@ -414,7 +415,7 @@ for(let i = 0; i <= 5; i++){
 2. In above countries array, check if there is a country or countries containing the word 'land'. If there are countries containing 'land', print it as array. If there is no country containing the word 'land', print 'All these countries are without land'.
 
     ```sh
-    ['Finland', 'Iceland']
+    ['Finland','Ireland', 'Iceland']
     ```
 
 3. In above countries array, check if there is  a country or countries end with a substring 'ia'. If there are countries end with, print it as array. If there is no country containing the word 'ai', print 'These are countries ends without ia'.

07_Day_Functions/07_day_functions.md

@@ -502,10 +502,13 @@ console.log('Weight of an object in Newton: ', weightOfObject(100, 1.62)) // gra
 
 ### Function declaration versus Arrow function
 
-It ill be covered in other time
+It Will be covered in other section.
 
 🌕 You are a rising star, now you knew function . Now, you are super charged with the power of functions. You have just completed day 7 challenges and you are 7 steps a head in to your way to greatness. Now do some exercises for your brain and for your muscle.
 
+## Testimony
+Now it is time to express your thoughts about the Author and 30DaysOfJavaScript. You can leave your testimonial on this [link](https://testimonify.herokuapp.com/)
+
 ## 💻 Exercises
 
 ### Exercises: Level 1
@@ -617,7 +620,7 @@ It ill be covered in other time
 
 ### Exercises: Level 3
 
-1. Modify question number n . Declare a function name _userIdGeneratedByUser_. It doesn’t take any parameter but it takes two inputs using prompt(). One of the input is the number of characters and the second input is the number of ids which are supposed to be generated.
+1. Modify the _userIdGenerator_ function. Declare a function name _userIdGeneratedByUser_. It doesn’t take any parameter but it takes two inputs using prompt(). One of the input is the number of characters and the second input is the number of ids which are supposed to be generated.
 
     ```sh
     userIdGeneratedByUser()

08_Day_Objects/08_day_objects.md

@@ -52,7 +52,7 @@ Variables scopes can be:
 Variable can be declared globally or locally or window scope. We will see both global and local scope.
 Anything declared without let, var or const is scoped at window level.
 
-Let us image we have a scope.js file.
+Let us imagine that we have a scope.js file.
 
 ### Window Scope
 
@@ -102,23 +102,25 @@ let a = 'JavaScript' // is a global scope it will be found anywhere in this file
 let b = 10 // is a global scope it will be found anywhere in this file
 function letsLearnScope() {
   console.log(a, b) // JavaScript 10, accessible
-  let c = 30
+  let value = false
   if (true) {
     // we can access from the function and outside the function but 
     // variables declared inside the if will not be accessed outside the if block
     let a = 'Python'
     let b = 20
+    let c = 30
     let d = 40
+    value = !value
     console.log(a, b, c) // Python 20 30
   }
   // we can not access c because c's scope is only the if block
-  console.log(a, b) // JavaScript 10
+  console.log(a, b, value) // JavaScript 10 true
 }
 letsLearnScope()
 console.log(a, b) // JavaScript 10, accessible
 ```
 
-Now, you have an understanding of scope. A variable declared with *var* only scoped to function but variable declared with *let* or *const* is block scope(function block, if block, loop etc). Block in JavaScript is a code in between two curly brackets ({}).
+Now, you have an understanding of scope. A variable declared with *var* only scoped to function but variable declared with *let* or *const* is block scope(function block, if block, loop block, etc). Block in JavaScript is a code in between two curly brackets ({}).
 
 ```js
 //scope.js
@@ -163,7 +165,7 @@ if (true){
 for(let i = 0; i < 3; i++){
   console.log(i) // 1, 2, 3
 }
-// console.log(i), Uncaught ReferenceError: gravity is not defined
+// console.log(i), Uncaught ReferenceError: i is not defined
 
 ```
 
@@ -432,7 +434,7 @@ console.log(copyPerson.hasOwnProperty('score'))
 ### Exercises: Level 2
 
 1. Find the person who has many skills in the users object.
-1. Count logged in users,count users having greater than equal to 50 points from the following object.
+1. Count logged in users, count users having greater than equal to 50 points from the following object.
 
    ````js
    const users = {

09_Day_Higher_order_functions/09_day_higher_order_functions.md

@@ -81,23 +81,22 @@ const higherOrder = n => {
     }
     return doWhatEver
   }
-​
   return doSomething
 }
 console.log(higherOrder(2)(3)(10))
 ```
 
-Let us see were we use call back functions.For instance the _forEach_ method uses call back.
+Let us see were we use call back functions. For instance the _forEach_ method uses call back.
 
 ```js
 const numbers = [1, 2, 3, 4]
 ​
 const sumArray = arr => {
   let sum = 0
-  const callBack = function(element) {
+  const callback = function(element) {
     sum += element
   }
-  numbers.forEach(callback)
+  arr.forEach(callback)
   return sum
 
 }
@@ -115,7 +114,7 @@ const numbers = [1, 2, 3, 4]
 ​
 const sumArray = arr => {
   let sum = 0
-  numbers.forEach(function(element) {
+  arr.forEach(function(element) {
     sum += element
   })
   return sum
@@ -128,20 +127,20 @@ console.log(sumArray(numbers))
 15
 ```
 
-### setting time
+### Setting time
 
-In JavaScript we can execute some activity on certain interval of time or we can schedule(wait) for sometime to execute some activities.
+In JavaScript we can execute some activities in a certain interval of time or we can schedule(wait) for some time to execute some activities.
 
 - setInterval
 - setTimeout
 
-#### setInterval
+#### Setting Interaval using a setInterval function
 
 In JavaScript, we use setInterval higher order function to do some activity continuously with in some interval of time. The setInterval global method take a callback function and a duration as a parameter. The duration is in milliseconds and the callback will be always called in that interval of time.
 
 ```js
 // syntax
-function callBack() {
+function callback() {
   // code goes here
 }
 setInterval(callback, duration)
@@ -151,10 +150,10 @@ setInterval(callback, duration)
 function sayHello() {
   console.log('Hello')
 }
-setInterval(sayHello, 2000) // it prints hello in every 2 seconds
+setInterval(sayHello, 1000) // it prints hello in every second, 1000ms is 1s
 ```
 
-#### setTimeout
+#### Setting a time using a setTimeout
 
 In JavaScript, we use setTimeout higher order function to execute some action at some time in the future. The setTimeout global method take a callback function and a duration as a parameter. The duration is in milliseconds and the callback wait for that amount of time.
 
@@ -195,9 +194,8 @@ arr.forEach((element, index, arr) => console.log(index, element, arr))
 
 ```js
 let sum = 0;
-const numbers = [1,2,3,4,5];
-numbers.forEach(num => console.log(num)))
-
+const numbers = [1, 2, 3, 4, 5];
+numbers.forEach(num => console.log(num))
 console.log(sum)
 ```
 
@@ -211,8 +209,8 @@ console.log(sum)
 
 ```js
 let sum = 0;
-const numbers = [1,2,3,4,5];
-numbers.forEach(num => sum += num))
+const numbers = [1, 2, 3, 4, 5];
+numbers.forEach(num => sum += num)
 
 console.log(sum)
 ```
@@ -349,6 +347,7 @@ console.log(countriesHaveFiveLetters)
 ```js
 const scores = [
   { name: 'Asabeneh', score: 95 },
+   { name: 'Lidiya', score: 98 },
   { name: 'Mathias', score: 80 },
   { name: 'Elias', score: 50 },
   { name: 'Martha', score: 85 },
@@ -360,7 +359,7 @@ console.log(scoresGreaterEight)
 ```
 
 ```sh
-[{name: 'Asabeneh', score: 95}, {name: 'Martha', score: 85},{name: 'John', score: 100}]
+[{name: 'Asabeneh', score: 95}, { name: 'Lidiya', score: 98 },{name: 'Martha', score: 85},{name: 'John', score: 100}]
 ```
 
 ### reduce
@@ -391,7 +390,7 @@ _every_: Check if all the elements are similar in one aspect. It returns boolean
 
 ```js
 const names = ['Asabeneh', 'Mathias', 'Elias', 'Brook']
-const areAllStr = names.every((name) => typeof name === 'string')
+const areAllStr = names.every((name) => typeof name === 'string') // Are all strings?
 
 console.log(arrAllStr)
 ```
@@ -402,11 +401,9 @@ true
 
 ```js
 const bools = [true, true, true, true]
-const areAllTrue = bools.every((b) => {
-  return b === true
-})
+const areAllTrue = bools.every((b) => b === true) // Are all true? 
 
-console.log(areAllTrue) //true
+console.log(areAllTrue) // true
 ```
 
 ```sh
@@ -448,9 +445,7 @@ const scores = [
   { name: 'John', score: 100 },
 ]
 
-const score = scores.find((user) => {
-  return user.score > 80
-})
+const score = scores.find((user) => user.score > 80)
 console.log(score)
 ```
 
@@ -481,15 +476,13 @@ _some_: Check if some of the elements are similar in one aspect. It returns bool
 const names = ['Asabeneh', 'Mathias', 'Elias', 'Brook']
 const bools = [true, true, true, true]
 
-const areSomeTrue = bools.some((b) => {
-  return b === true
-})
+const areSomeTrue = bools.some((b) =>  b === true)
 
 console.log(areSomeTrue) //true
 ```
 
 ```js
-const areAllStr = names.some((name) => typeof name === 'number')
+const areAllStr = names.some((name) => typeof name === 'number') // Are all strings ?
 console.log(areAllStr) // false
 ```
 
@@ -556,7 +549,7 @@ users.sort((a, b) => {
   return 0
 })
 console.log(users) // sorted ascending
-//[{…}, {…}, {…}, {…}]
+// [{…}, {…}, {…}, {…}]
 ```
 
 🌕 You are doing great.Never give up because great things take time. You have just completed day 9 challenges and you are 9 steps a head in to your way to greatness. Now do some exercises for your brain and for your muscle.

10_Day_Sets_and_Maps/10_day_Sets_and_Maps.md

@@ -245,7 +245,7 @@ Set(6) {1, 2, 3, 4, 5,6}
 
 ### Intersection of sets
 
-To find an intersection of two sets can be achieved using filter. Lets find the union of set A and set B (A ∩ B)
+To find an intersection of two sets can be achieved using filter. Lets find the intersection of set A and set B (A ∩ B)
 
 ```js
 let a = [1, 2, 3, 4, 5]
@@ -388,8 +388,8 @@ Norway Oslo
 ### Exercises:Level 1
 
 ```js
-const a = {4, 5, 8, 9}
-const b = {3, 4, 5, 7}
+const a = [4, 5, 8, 9]
+const b = [3, 4, 5, 7]
 const countries = ['Finland', 'Sweden', 'Norway']
 ```
 
@@ -432,9 +432,9 @@ const countries = ['Finland', 'Sweden', 'Norway']
   // Your output should look like this
   console.log(mostSpokenLanguages(countries, 3))
   [
-  {'English':91},
-  {'French':45},
-  {'Arabic':25}
+  {English:91},
+  {French:45},
+  {Arabic:25}
   ]
 ```
 

11_Day_Destructuring_and_spreading/11_day_destructuring_and_spreading.md

@@ -209,7 +209,7 @@ const rectangle = {
   height: 10,
   area: 200
 }
-let { width: w, heigh: h, area: a, perimeter: p } = rectangle
+let { width: w, height: h, area: a, perimeter: p } = rectangle
 
 console.log(w, h, a, p)
 ```
@@ -226,7 +226,7 @@ const rectangle = {
   height: 10,
   area: 200
 }
-let { width, heigh, area, perimeter = 60 } = rectangle
+let { width, height, area, perimeter = 60 } = rectangle
 
 console.log(width, height, area, perimeter) //20 10 200 60
 //Lets modify the object:width to 30 and perimeter to 80
@@ -239,8 +239,8 @@ const rectangle = {
   area: 200,
   perimeter: 80
 }
-let { width, heigh, area, perimeter = 60 } = rectangle
-console.log(width, height, area, perimeter) //20 10 200 80
+let { width, height, area, perimeter = 60 } = rectangle
+console.log(width, height, area, perimeter) //30 10 200 80
 ```
 
 Destructuring keys as a function parameters. Lets create a function which take a rectangle object and it return a perimeter of a rectangle.
@@ -695,4 +695,4 @@ const users = [
 ```
 🎉 CONGRATULATIONS ! 🎉
 
-[<< Day 10](../10_Day_Sets_and_Maps/10_day_Sets_and_Maps.md) | [Day 12>>](../12_Day_Regular_expressions/12_day_regular_expressions.md)
+[<< Day 10](../10_Day_Sets_and_Maps/10_day_Sets_and_Maps.md) | [Day 12 >>](../12_Day_Regular_expressions/12_day_regular_expressions.md)

17_Day_Web_storages/17_day_web_storages.md

@@ -38,7 +38,7 @@
 
 Web Storage(sessionStorage and localStorage) is a new HTML5 API offering important benefits over traditional cookies. Before HTML5, application data had to be stored in cookies, included in every server request. Web storage is more secure, and large amounts of data can be stored locally, without affecting website performance. The data storage limit of cookies in many web browsers is about 4 KB per cookie. We Storages can store far larger data (at least 5MB) and never transferred to the server. All sites from the same or one origin can store and access the same data.
 
-The data being stored can be accessed using JavaScript, which gives you the ability to leverage client-side scripting to do many things that have traditionally involved server-side programming and relational databases. The are are two Web Storage objects:
+The data being stored can be accessed using JavaScript, which gives you the ability to leverage client-side scripting to do many things that have traditionally involved server-side programming and relational databases. There are two Web Storage objects:
 
 - sessionStorage
 - localStorage