Jagathishrex

function removeElement(arr, ele){
  const index = arr.indexOf(2);  
  if (index > -1) {
    arr.splice(index, 1);
  }
}

const numbers = [1, 2, 3, 4];
removeElement(numbers, 2);

Jagathishrex

// print key-values of an object recursively 

function flattenObject(obj) {
  for (let key in obj) {
    if (typeof obj[key] === 'string') {
      console.log(key, obj[key]);
    }
    if (typeof obj[key] === 'object') {
      flattenObject(obj[key]);
    }

Jagathishrex

function reverseInt(n) {
    let reversedInteger = n.toString().split('').reverse().join('');

    return parseInt(reversedInteger) * Math.sign(n);
}

console.log(reverseInt(-12)); // -21

console.log(reverseInt(-1)); // -1

Jagathishrex

var a = [1,2,3];
var b = true;
var c = [4,5,6];

const concatAb = [].concat(a, b); // [1, 2, 3, true]
const concatAb = [].concat(a, b); // [1, 2, 3, 4, 5, 6]

Jagathishrex

                                        sorting numbers 

const arr = [1, 20, 8, 4, 9, 0];
//ascending order
arr.sort((a, b) => a - b); // [0, 1, 4, 8, 9, 20]
// Sort in descending order
arr.sort((a, b) => b - a); // [20, 9, 8, 4, 1, 0]

                                         sorting string  
const strArr = ['Java', 'Python', 'HTML', "css", "CSS"];

Jagathishrex

function hasDuplicates(array) { 
    let uniqueValues = new Set(array);  // set --> contains only unique values 
    return uniqueValues.size !== array.length;
}

hasDupicates([1,2,3]); // false
hasDupicates([1,2,3,1]); // true

Jagathishrex

// Returns a random number(float) between min (inclusive) and max (exclusive) 

const getRandomNumber = (min, max) => Math.random() * (max - min) + min;

getRandomNumber(2, 10)

 // Returns a random number(int) between min (inclusive) and max (inclusive)

const getRandomNumberInclusive =(min, max)=> {
    min = Math.ceil(min);

Jagathishrex

How to generate a random number in a given range

// Returns a random number(float) between min (inclusive) and max (exclusive) 

const getRandomNumber = (min, max) => Math.random() * (max - min) + min;

getRandomNumber(2, 10)

 // Returns a random number(int) between min (inclusive) and max (inclusive)

Jagathishrex

let num = new Array(3); // creating an empty array with length 3

console.log(num); // [empty × 3]

console.log(num[0]); // undefined 

// the callback function passed to Array.some method will not check the callback for unassigned values 

num.some(a => {console.log(a); return a === undefined }) // false

Jagathishrex

const lang = ["Java", "JavaScript"];
 
let hasJavaScript = function(currentElement, index, array){
  console.log(`currentElement = ${currentElement}`);
  console.log(`index = ${index}`);
  console.log("-------------------------");
  return array[index] === "JavaScript";
}
// element found in 1st index 
lang.findIndex( hasJavaScript ); // 1