Suppose we have an array like this −const arr = [2, 42, 82, 122, 162, 202, 242, 282, 322, 362];We are required to write a JavaScript function that takes in one such array and a number, say n.The function should return the index of item from the array which is closest to the number n.Therefore, let’s write the code for this function −ExampleThe code for this will be −const arr = [2, 42, 82, 122, 162, 202, 242, 282, 322, 362]; const closestIndex = (num, arr) => {    let curr = arr[0], diff = Math.abs(num - curr);    let ... Read More

We are required to write a JavaScript function that should repeat the even number inside the same array.For example, given the following array −const arr = [1, 2, 5, 6, 8];OutputWe should get the output −const output = [1, 2, 2, 5, 6, 6, 8, 8];Therefore, let’s write the code for this function −ExampleThe code for this will be −const arr = [1, 2, 5, 6, 8]; const repeatEvenNumbers = arr => {    let end = arr.length -1;    for(let i = end; i > 0; i--){       if(arr[i] % 2 === 0){          arr.splice(i, 0, arr[i]);       };    };    return arr; }; console.log(repeatEvenNumbers(arr));OutputThe output in the console will be −[    1, 2, 2, 5,    6, 6, 8, 8 ]

Given a sequence of integers as an array, determine whether it is possible to obtain a strictly increasing sequence by removing no more than one element from the array.Note: sequence a0, a1, ..., an is considered to be strictly increasing if a0 < a1 < ... < an. Sequences containing only one element are also considered to be strictly increasing.Example, for sequence = [1, 3, 2, 1], the output should be −almostIncreasingSequence(sequence) = false.There is no one element in this array that can be removed in order to get a strictly increasing sequence.For sequence = [1, 3, 2], the output ... Read More

Suppose we have an array like this −const arr = [    [1, 2, 3, 4],    [12, 13, 14, 5],    [11, 16, 15, 6],    [10, 9, 8, 7] ];The array is bound to be a square matrix.We are required to write a JavaScript function that takes in this array and constructs a new array by taking elements and spiraling in until it converges to center. A snail trail spiraling around the outside of the matrix and inwards.Therefore, the output for the above array should be −const output = [1, 2, 3, 4, 5, 6, 7, 8, 9, ... Read More

In this article, the given task is to get the best way of finding the length of a JSON object in JavaScript. Input-Output Scenario Let’s look into this input-output scenario. Consider there is an object with some keys and values in it. we need to get the length of the object. const MyObj = { Name: "Mike", Age: 34 }; document.write(Object.keys(MyObj).length); // Output: 2 Using Object.keys() The Object.keys() method will return the output in form of array of a given object’s own enumerable properties names. It will return the output of keys ... Read More

A JSON (JavaScript object notation) Object is always surrounded by the curly braces {}. The values must be a valid JSON data type, and the keys must be strings. JSON supports the following data types: number, string, object, Boolean, array, and null. There has to be a colon (":") separating the keys and values. A comma separates each key and value pair. Following is the syntax of JSON Object − JSONObject = {} Following is the basic declaration of JSON Object in JavaScript − JSONObject = { "name" : "Suriya", ... Read More

Suppose, we have an array and objects like these −Objects:const main = [    {name: "Karan", age: 34},    {name: "Aayush", age: 24},    {name: "Ameesh", age: 23},    {name: "Joy", age: 33},    {name: "Siddarth", age: 43},    {name: "Nakul", age: 31},    {name: "Anmol", age: 21}, ];Array:const names = ["Karan", "Joy", "Siddarth", "Ameesh"];We are required to write a JavaScript function that takes in two such arrays and filters the first array in place to contain only those objects whose name property is included in the second array.Therefore, let’s write the code for this function −ExampleThe code for this ... Read More

Given two arrays and the task is to convert those two arrays into a JSON object. Where the first array elements are keys of the object and the second array elements are values of the object. Input-Output Scenario Let’s look into the scenario of how two arrays will be converted into a JSON object. Consider two arrays are having some elements. Now, we need to convert these two arrays into a JSON object. Array1 = [1, 2, 3, 4]; Array2 = ['A', 'B', 'C', 'D']; Output = {"1":"A", "2":"B", "3":"C", "4":"D"} //JSON object In this article, ... Read More

We are required to write a JavaScript function that takes in a string that represents a number.Replace the leading zero with spaces in the number. Make sure the prior spaces in number are retained.For example: If the string value is defined as −"004590808"Then the output should come as −"4590808"ExampleThe code for this will be −const str = ' 004590808'; const replaceWithSpace = str => {    let replaced = '';    const regex = new RegExp(/^\s*0+/);    replaced = str.replace(regex, el => {       const { length } = el;       return ' '.repeat(length);    });    return replaced; }; console.log(replaceWithSpace(str));OutputThe output in the console will be −4590808

We are required to write a JavaScript function that takes in a number and calculates its square root without using the Math.sqrt() function.Therefore, let’s write the code for this function −ExampleThe code for this will be −const square = (n, i, j) => {    let mid = (i + j) / 2;    let mul = mid * mid;    if ((mul === n) || (Math.abs(mul - n) < 0.00001)){       return mid;    }else if (mul < n){       return square(n, mid, j);    }else{       return square(n, i, mid);    } ... Read More