JavaScript Combine Two Arrays

Array.prototype.push()

The push() method adds one or more elements to the end of an array and returns the new length of the array.

Syntax

push(element0)
push(element0, element1)
push(element0, element1, ... , elementN)

Example

const array1 = [1, 2, 3, 4];
const array2 = [5, 6, 7, 8];
array1.push(...array2);
// expected output: Array [1, 2, 3, 4, 6, 7, 8]

Array.prototype.concat()

The concat() method is used to merge two or more arrays. This method does not change the existing arrays, but instead returns a new array.

Syntax

concat()
concat(value0)
concat(value0, value1)
concat(value0, value1, ... , valueN)

Example

const array1 = ['a', 'b', 'c'];
const array2 = ['d', 'e', 'f'];
const array3 = array1.concat(array2);

console.log(array3);
// expected output: Array ["a", "b", "c", "d", "e", "f"]