JS: Array.prototype.push

By Xah Lee. Date: 2015-07-31. Last updated: 2023-01-26.

arrayX.push(new1, new2, etc)

Adds items to the end of the array arrayX. Return the new length.

const xx = [3];

const xy = xx.push(7, [8]);

console.log(xy === 3);
console.log(JSON.stringify(xx) === "[3,7,[8]]");

To join arrays by flattening 1 level, see Array.prototype.concat .

To flatten nested array, see Array.prototype.flat .