Answer to Question #170074 in HTML/JavaScript Web Application for Chandra sena reddy

Question

Square at Alternate Indices

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.Input

• The input will be a single line containing an array myArray

Output

• The output should be a single line containing an array with alternate numbers squared

Constraints

• Each value in the array must be a number

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 ]

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));