Merging two or more arrays with vanilla JS

The Array.concat() method lets you merge two or more arrays together. It returns a new array.

var sandwiches1 = ['turkey', 'tuna', 'blt'];
var sandwiches2 = ['chicken', 'pb&j', 'tuna'];
var allSandwiches = sandwiches1.concat(sandwiches2);
// sandwiches1: ['turkey', 'tuna', 'blt']
// sandwiches2: ['chicken', 'pb&j', 'tuna']
// allSandwiches: ['turkey', 'tuna', 'blt', 'chicken', 'pb&j', 'tuna']

Here’s a demo.

One thing you’ll notice is that 'tuna' shows up twice. Next week, we’ll look at how to remove duplicates from an array.

Array.concat() works in all modern browsers, and at least back to IE6.