Javascript: How to Use the push, pop, and unshift methods in the array

There are three types of JavaScript declared arrays. The first one is as follows:

VaR AA = new array ();

1. Add a field to the first position in the array using the unshift () method. This method must be filled with at least one value and the returned value is the length of the array.

AA. unshift ("123", "optional", "optional ");

2. Insert a field to the last position of the array using the push () method. This method must be filled with at least one value and the returned value is the length of the array.

AA. Push ("456", "optional", "optional ");

3. You can use the POP () method to return the last value of the array. After the POP () method is called, the array deletes the last value and the length of the array is reduced by 1. if the array is null, call this method to return the undefined value.

AA. Pop ();