JavaScript - create array of all integers between two numbers (inclusive)

In this article, we would like to show you how to create an array of all integers between two numbers in JavaScript.

Quick solution:

// ONLINE-RUNNER:browser;

var array = [];

var startNumber = 1;
var endNumber = 3;

for (var i = startNumber; i <= endNumber; ++i) {
    array.push(i);
}

console.log(array); // [ 1, 2, 3 ]

Note:

The startNumber can't be higher than endNumer and they both have to be integers.

Reusable arrow function (ES6+)

In this example, we create a reusable arrow function that creates array of all integers between start and end numbers. In this solution, the start number can be higher than the end number.

// ONLINE-RUNNER:browser;

const createArray = (start, end) => {
    const array = [];
    if (end > start) {
        for (let i = start; i <= end; ++i) {
            array.push(i);
        }
    } else {
        for (let i = start; i >= end; --i) {
            array.push(i);
        }
    }
    return array;
};


// Usage example:

const array1 = createArray(0, 2);
const array2 = createArray(2, 4);
const array3 = createArray(2, 0);

console.log(array1); // [ 0, 1, 2 ]
console.log(array2); // [ 2, 3, 4 ]
console.log(array3); // [ 2, 1, 0 ]

References

1. Array.prototype.push() - JavaScript | MDN