AnkitMaheshwariIn

// declare a global variable
var globalVar = "abc";

// self invoking parent/outer function
(function outerFunction (outerArg) { // begin scope of outerFunction
  // declare a variable in outerFunction scope
  var outerFuncVar = 'x';    
  // self-invoking closure function - inner function
  (function innerFunction (innerArg) { // begin of scope innerFunction
    // variable declared in innerFunction scope

AnkitMaheshwariIn

// declare a function
function foo() {
  // this refers to the reference over which this function is calling
	console.log( this.bar );
}

// declare a global variable bar
var bar = "global";

// declare an object with 2 key-value

AnkitMaheshwariIn

// declare a conterFunc
function counterFunc() {
  // declare a private var
  var counterVar = 0;
  // return an object, with functions add & get that allows us
  // to modify the private variable `counterVar`
  return {
    add: function(increment) { counterVar += increment; },
    get: function() { return `The value of counterVar is ${counterVar}` }
  }

AnkitMaheshwariIn

// Given two strings
var firstWord = "Mary";
var secondWord = "Army";

// call a function to check if given two words are Anagrams
isAnagram(firstWord, secondWord); // Output is: true

function isAnagram(first, second) {
  // For case insensitivity, change both words to lowercase.
  var a = first.toLowerCase();

AnkitMaheshwariIn

// iterate for-loop 100 times
for (let i = 1; i <= 100; i++) {
  // check if `i` is isFizz - that is multiples of 3
  const isFizz = i % 3 == 0;
  // check if `i` is isBuzz - that is multiples of 5
  const isBuzz = i % 5 == 0;
  
  // print output: if it's isFizz there could be two possibility 'Fizz' or 'FizzBizz' and
  // if it's not isFizz then it will be 'isBuzz' or nothing
  console.log(isFizz ? (isBuzz ? 'FizzBuzz' : 'Fizz') : isBuzz ? 'Buzz' : i);

AnkitMaheshwariIn

function duplicate(arr) {
  // to duplicate an array use concat an array
  return arr.concat(arr);
}

// call a function to duplicate array
const output = duplicate([1, 2, 3, 4, 5]); 
console.log(output) // Output: [1,2,3,4,5,1,2,3,4,5]

AnkitMaheshwariIn

function isInt(num) {
  // check if remainder left when we divide by 1
  return num % 1 === 0;
}

// call isInt function
console.log(isInt(4)); // true
console.log(isInt(12.2)); // false
console.log(isInt(0.3)); // false

AnkitMaheshwariIn

var arrayList = ['a', 'b', 'c', 'd', 'e', 'f']; // Created array
var anotherArrayList = arrayList;  // Referenced arrayList by another variable
arrayList.length = 0; // Empty the array by setting length to 0, this will empty all reference
console.log(anotherArrayList); // Output []

AnkitMaheshwariIn

var arrayList = ['a', 'b', 'c', 'd', 'e', 'f']; // Created an array
var anotherArrayList = arrayList;  // Referenced arrayList by another variable
arrayList = []; // Empty an arrayList
console.log(anotherArrayList); // anotherArrayList remains same, that is still pointing to old reference
// Output ['a', 'b', 'c', 'd', 'e', 'f']

AnkitMaheshwariIn

const arrayList = [1 , 2, 3];
// check if arrayList is an Array or not
const isArr = Array.isArray(arrayList);
console.log(`Input arrayList is Array: ${isArr}`)