In this article, we will learn to check if a number is Narcissistic in JavaScript. A Narcissistic number is a number that equals the sum of its digits, each raised to the power of the total number of digits. We will explore two approaches to solve this problem an iterative method and a concise string manipulation technique. Narcissistic number A narcissistic number(also known as an Armstrong number) in a given number base b is a number that is the sum of its digits each raised to the power of the number of digits. For example − 153 = 1^3 + ... Read More

We have to write a function that takes in a string as one and only argument, and return its equivalent number.For example −one five seven eight -------> 1578 Two eight eight eight -------> 2888This one is pretty straightforward; we iterate over the array of words splitted by whitespace and keep adding the appropriate number to the result.The code for doing this will be −Exampleconst wordToNum = (str) => {    const legend = ['zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine'];    return str.toLowerCase().split(" ").reduce((acc, val) => {       const index = legend.indexOf(val);     ... Read More

Let’s say, we have to write a function that takes an array of numbers as argument. We have to return a new array with the products of each number except the index we are currently calculating product for.For example, if arr had 5 indices and we were creating the value for index 1, the numbers at index 0, 2, 3 and 4 would be multiplied. Similarly, if we were creating the value for index 2, the numbers at index 0, 1, 3 and 4 would be multiplied and so on.Note − It is guaranteed that all the elements inside the ... Read More

We have an array of Number literals like this −const numbers = [10, 6200, 20, 20, 350, 900, 26, 78, 888, 10000, 78, 15000, 200, 1280, 2000, 450];We are supposed to write a function that takes an array of numbers and a number between [0, 100], basically this number represents a certain percent. Let us denote this number by x for now.Now we have to return a subarray of first n elements of the original array that add up equal to or just less than the x % of the total sum of all array elements.Take a simpler example −const ... Read More

We have to write a function that removes every second character (starting from the very first character) from a string and appends all of those removed characters at the end in JavaScript.For example −If the string is "This is a test!" Then it should become "hsi etTi sats!"Therefore, let’s write the code for this function −Exampleconst string = 'This is a test!'; const separateString = (str) => {    const { first, second } = [...str].reduce((acc, val, ind) => {       const { first, second } = acc;       return {          first: ... Read More

We have an array of objects. Each object contains a few properties and one of these properties is age −const people = [    {       name: 'Anna',       age: 22    }, {       name: 'Tom',       age: 34    }, {       name: 'John',       age: 12    }, {       name: 'Kallis',       age: 22    }, {       name: 'Josh',       age: 19    } ]We have to write a function that takes in such an ... Read More

We are required to write a function that takes two numbers as arguments m and n, and it returns the sum of all even numbers that falls between m and n (both inclusive)For example −If m = 10 and n = -4The output should be 10+8+6+4+2+0+(-2)+(-4) = 24ApproachWe will first calculate the sum of all even numbers up to n and the sum of all even numbers up to m.Then we will check for the bigger of the two m and n. Subtract the sum of smaller from the sum of bigger which will eventually give us the sum between ... Read More

Let’s say, we have an array of objects with each object having exactly two properties, x and y that represent the coordinates of a point. We have to write a function that takes in this array and an object with x and y coordinates of a point and we have to sort the points (objects) in the array according to the distance from the given point (nearest to farthest).The Distance FormulaIt is a mathematical formula that states that the shortest distance between two points (x1, y1) and (x2, y2) in a two-dimensional plane is given by −$S=\sqrt{((x2-x1)^2+(y2-y1)^2)}$We will be using ... Read More

Let’s say, we have two arrays, one of String literals and another of objects.const data = [{    name: 'Kamlesh Kapasi',    uid: 123 }, {       name: 'Mahesh Babu',       uid: 129 }, {       name: 'Akshay Kapoor',       uid: 223 }, {       name: 'Vikas Gupta',       uid: 423 }, {       name: 'Mohit Dalal',       uid: 133 }, {       name: 'Rajkumar Hirani',       uid: 233 }, {       name: 'Joy',       uid: ... Read More

We have to write a function that takes an array and any number of strings as arguments. The task is to check if the strings occur within the array. If it does, we have to move that particular to the front of the array.Therefore, let’s write the code for this function −Exampleconst arr = ['The', 'weather', 'today', 'is', 'a', 'bit', 'windy.']; const pushFront = (arr, ...strings) => {    strings.forEach(el => {       const index = arr.indexOf(el);       if(index !== -1){          arr.unshift(arr.splice(index, 1)[0]);       };    }); }; pushFront(arr, 'today', ... Read More