Constructing an array of first n multiples of an input number in JavaScript

We are required to write a JavaScript function that takes in two numbers, let say m and n.

Our function should construct and return an array of first n natural multiples of m.

Problem Statement

Given two numbers m and n, we need to create a function that returns an array containing the first n multiples of m. For example, if m = 6 and n = 5, the function should return [6, 12, 18, 24, 30].

Method 1: Using a For Loop

The most straightforward approach is to use a for loop to iterate n times and multiply m by each iteration index:

const m = 6;
const n = 14;

const firstNMultiple = (m = 1, n = 1) => {
    const res = [];
    for(let i = 1; i 

[6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84]


Method 2: Using Array.from()

A more functional approach using Array.from() with a mapping function:

const getMultiples = (m, n) => {
    return Array.from({length: n}, (_, index) => m * (index + 1));
};

console.log(getMultiples(5, 8));


[5, 10, 15, 20, 25, 30, 35, 40]


Method 3: Using Array.fill() and map()

Another approach combining Array.fill() and map():

const createMultiples = (m, n) => {
    return new Array(n).fill(0).map((_, i) => m * (i + 1));
};

console.log(createMultiples(3, 6));


[3, 6, 9, 12, 15, 18]


Comparison

Conclusion

The for loop approach offers the best performance and readability for generating arrays of multiples. Array.from() provides a more functional style while maintaining good performance. Choose based on your coding style preferences and performance requirements.