Re-implementation of Array Higher Order Functions in JavaScript

mapExample.js

const square = (number) => {
    return number * number;
}

const double = (number) => {
    return number * 2;
}

const map = (array, operation, thisArg = undefined) => {
    const newArray = [];
    for (let index = 0; index < array.length; index++) {
        const element = array[index];
        const newElement = operation.call(thisArg, element,
                index, array);
        newArray.push(newElement);
    }
    return newArray;
}

const numbers = [1, 2, 3, 4, 5];
const squaredNumbers = map(numbers, square);
const doubledNumbers = map(numbers, double);

console.log('Original: ', numbers);
console.log('  Squared: ', squaredNumbers);
console.log('  Doubled: ', doubledNumbers);