JavaScript - copy array with append item operation

In this article, we would like to show you how to copy an array with appended item using JavaScript.

Quick solution:

// ONLINE-RUNNER:browser;

var myArray = [1, 2, 3];
var newItem = 4;

var result = [].concat(myArray, newItem);  // myArray.concat(newItem);

console.log(result);  // [ 1, 2, 3, 4 ]

Reusable function example

In this example, we create a reusable function that creates a copy of the given array with an item appended at the end.

// ONLINE-RUNNER:browser;

function appendItem(array, item) {
    return [].concat(array, item);  // array.concat(item);
}


// Usage example:

var array = [1, 2, 3];

var copy1 = appendItem(array, 4);
var copy2 = appendItem(array, 5);
var copy3 = appendItem(array, 6);

console.log(copy1);  // [ 1, 2, 3, 4 ]
console.log(copy2);  // [ 1, 2, 3, 5 ]
console.log(copy3);  // [ 1, 2, 3, 6 ]

See also

1. JavaScript - copy array with prepend item operation

2. JavaScript - copy array with replace item operation

3. JavaScript - copy array with remove item operation

References

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