Answer to Question #229528 in HTML/JavaScript Web Application for sonu

Question

Given an array myArray of numbers, write a function to square the alternate numbers of the myArray, starting from index 0 using the array method map.

Sample Input 1

[ 1, 2, 3, 4, 5 ]

Sample Output 1

[ 1, 2, 9, 4, 25 ]

Sample Input 2

[ 2, 4 ]

Sample Output 2

[ 4, 4 ]

"use strict";

process.stdin.resume();

process.stdin.setEncoding("utf-8");

let inputString = "";

let currentLine = 0;

process.stdin.on("data", (inputStdin) => {

 inputString += inputStdin;

});

process.stdin.on("end", (_) => {

 inputString = inputString.trim().split("\n").map((str) => str.trim());

 main();

});

function readLine() {

 return inputString[currentLine++];

}

/* Please do not modify anything above this line */

function main() {

 const myArray = JSON.parse(readLine());

  

 /* Write your code here */

}

Answer 1

const arr1 = [ 1, 2, 3, 4, 5 ];
const arr2 = [ 2, 4 ];

function squareAlternate(arr) {
    return arr.map( (item, index) => {
        if (index % 2 == 0) {
            return item *= item;
        } else return item;
    })
}

console.log(squareAlternate(arr1));
console.log(squareAlternate(arr2));