Found 9315 Articles for Object Oriented Programming

Convert number to a reversed array of digits in JavaScript

AmitDiwan
Updated on 09-Oct-2020 11:20:15

115 Views

Given a non-negative integer, we are required to write a function that returns an array containing a list of independent digits in reverse order.For example:348597 => The correct solution should be [7,9,5,8,4,3]The code for this will be −const num = 348597; const reverseArrify = num => {    const numArr = String(num).split('');    const reversed = [];    for(let i = numArr.length - 1; i >= 0; i--){       reversed[i] = +numArr.shift();    };    return reversed; }; console.log(reverseArrify(num));Following is the output on console −[ 7, 9, 5, 8, 4, 3 ]

Distance between 2 duplicate numbers in an array JavaScript

AmitDiwan
Updated on 09-Oct-2020 11:18:54

103 Views

We are required to write a JavaScript function that takes in an array of numbers that contains at least one duplicate pair of numbers.Our function should return the distance between all the duplicate pairs of numbers that exist in the array.The code for this will be −const arr = [2, 3, 4, 2, 5, 4, 1, 3]; const findDistance = arr => {    var map = {}, res = {};    arr.forEach((el, ind) => {       map[el] = map[el] || [];       map[el].push(ind);    });    Object.keys(map).forEach(el => {       if (map[el].length > ... Read More

Hyphen string to camelCase string in JavaScript

AmitDiwan
Updated on 09-Oct-2020 11:16:54

145 Views

Suppose, we have a string that contains words separated by hyphens like this −const str = 'this-is-an-example';We are required to write a JavaScript function that takes in one such string and converts it into a camelCase string.For the above string, the output should be −const output = 'thisIsAnExample';The code for this will be −const str = 'this-is-an-example'; const changeToCamel = str => {    let newStr = '';    newStr = str    .split('-')    .map((el, ind) => {       return ind && el.length ? el[0].toUpperCase() + el.substring(1)       : el;    })    .join('');    return newStr; }; console.log(changeToCamel(str));Following is the output on console −thisIsAnExample

Finding closest pair sum of numbers to a given number in JavaScript

AmitDiwan
Updated on 09-Oct-2020 11:14:20

213 Views

We are required to write a JavaScript function that takes in an array of Numbers as the first argument and a Number as the second argument.The function should return an array of two numbers from the original array whose sum is closest to the number provided as the second argument.The code for this will be −const arr = [1, 2, 3, 4, 5, 6, 7]; const num = 14; const closestPair = (arr, sum) => {    let first = 0, second = 0;    for(let i in arr) {       for(let j in arr) {     ... Read More

Get max value per key in a JavaScript array

AmitDiwan
Updated on 09-Oct-2020 11:12:28

402 Views

Suppose, we have an array of objects like this −const arr = [    {a:1, b:"apples"},    {a:3, b:"apples"},    {a:4, b:"apples"},    {a:1, b:"bananas"},    {a:3, b:"bananas"},    {a:5, b:"bananas"},    {a:6, b:"bananas"},    {a:3, b:"oranges"},    {a:5, b:"oranges"},    {a:6, b:"oranges"},    {a:10, b:"oranges"} ];We are required to write a JavaScript function that takes in one such array and returns an array of objects.The array should contain an object for each unique value of "b" property where the "a" property has the highest value.The code for this will be −const arr = [    {a:1, b:"apples"},    {a:3, ... Read More

Finding transpose of a 2-D array JavaScript

AmitDiwan
Updated on 09-Oct-2020 11:10:00

168 Views

We are required to write a JavaScript function that takes in a two-dimensional array and returns its transposed array.The code for this will be −Method 1: Using Array.prototype.forEach()const arr = [    [0, 1],    [2, 3],    [4, 5] ]; const transpose = arr => {    const res = [];    arr.forEach((el, ind) => {       el.forEach((elm, index) => {          res[index] = res[index] || [];          res[index][ind] = elm;       });    });    return res; }; console.log(transpose(arr));Method 2: Using Array.prototype.reduce()const arr = [   ... Read More

Hexadecimal color to RGB color JavaScript

AmitDiwan
Updated on 09-Oct-2020 11:08:01

137 Views

We are required to write a JavaScript function that takes in a hexadecimal color and returns its RGB representation.The function should return an object containing the respective values of red green and blue color −For example:hexToRgb('#0080C0') should return 0, 128, 192The code for this will be −const hex = '#0080C0'; const hexToRGB = hex => {    let r = 0, g = 0, b = 0;    // handling 3 digit hex    if(hex.length == 4){       r = "0x" + hex[1] + hex[1];       g = "0x" + hex[2] + hex[2];       ... Read More

RGB color to hexadecimal color JavaScript

AmitDiwan
Updated on 09-Oct-2020 11:05:17

235 Views

We are required to write a JavaScript function that takes in a RGB color and returns its hexadecimal representation.The function should take in an object containing three numbers representing the respective values of red green and blue color.For example:rgbToHex(0, 128, 192) should return '#0080C0'The code for this will be −const rgbColor = {    red: 0,    green: 51,    blue: 155 } function rgbToHex({    red: r,    green: g,    blue: b }) {    const prefix = '#';    const hex = prefix + ((1

How to replace before first forward slash - JavaScript?

AmitDiwan
Updated on 03-Oct-2020 15:38:48

670 Views

Let’s say the following is our string with forward slash −var queryStringValue = "welcome/name/john/age/32"To replace before first forward slash, use replace() along with regular expressions.ExampleFollowing is the code −var regularExpression = /^[^/]+/ var queryStringValue = "welcome/name/john/age/32" var replacedValue = queryStringValue.replace(regularExpression, 'index'); console.log("Original value="+queryStringValue); console.log("After replacing the value="+replacedValue);To run the above program, you need to use the following command −node fileName.js. Here, my file name is demo245.js.OutputThis will produce the following output on console −PS C:\Users\Amit\javascript-code> node demo245.js Original value=welcome/name/john/age/32 After replacing the value=index/name/john/age/32Read More

Call a function with onclick() – JavaScript?

AmitDiwan
Updated on 03-Oct-2020 15:37:10

3K+ Views

Let’s say the following is our button −Press MeWe need to call a function on the click of above button.ExampleFollowing is the code − Live Demo            Document        Press Me    function displayingMessageOnButtonClick() {       const showMessage = document.getElementById('showTheTextMessage');       showMessage.innerHTML = 'Welcome to Javascript Program...';       showMessage.style.display = 'block';    } To run the above program, save the file name anyName.html(index.html). Right click on the file and select the option “Open with live server” in VS Code editor −OutputThe output is as follows −Now, press the button. Following is the output −

Advertisements