Push

One can push certain items to an array making the last index the newly added item. It changes the length of an array and returns a new length.

Here's the syntax for using push:

array.push(element1[, ...[, elementN]]);

The element1, ..., elementN arguments represent the elements to be added to the end of the array.

For example:

let array = [1, 2, 3]; 
array.push(4); 

console.log(array); 

// Result: array = [1, 2, 3, 4]

You can also use push to add elements to the end of an array-like object (such as an arguments object or a NodeList object) by first converting it to an array using the Array.prototype.slice() method:

function printArguments() {
  let args = Array.prototype.slice.call(arguments);
  args.push('d', 'e', 'f');
  console.log(args);
}

printArguments('a', 'b', 'c'); // Result: ["a", "b", "c", "d", "e", "f"]

Note: The push method modifies the original array. It does not create a new array.