In the JavaScript array, the SHIFT () and push (), Unshift (), and Pop () action methods use the

The JavaScript array specifically provides the push and pop () methods to implement a stack-like behavior. Take a look at the following example:

var colors=new Array (); Create an array

var Count=colors.push ("Red", "green"); Pushes two entries to return the length of the modified array

alert (count); 2 Returns the length of the modified array

var item=colors.pop (); Get the last one

alert (item); "Green"

alert (colors.length); 1

Queue method:

Using the shift () and push () methods together, you can use arrays as you would with queues:

var colors=new Array ();

var Count=colors.push ("Red", "green"); Push in two items

alert (count); 2

Count= Colors.push ("Black"); Add an item from the end of the array, at which point the order of the array is: "Red", "green", "black"

alert (count); 3

var item=colors.shift (); Get the first item

alert (item); "Red"

alert (colors.length); 2

As you can see from the example:

Shift () Method: Removes the first item in the array and returns the item

Push () Method: Add an item from the end of the array

If you want to do the opposite, you can use the

Unshift () Method: Add an item to the front of the array

Pop () Method: Remove an item from the end of the array

var colors=new Array ();

var count=colors.unshift ("Red", "green");//push in two

alert (count); 2

Count=colors.unshift ("Black"); Add items from the front of the array, at which point the order of the array is: "Black", "red", "green"

alert (count); 3

var item=colors.pop ();

alert (item); Remove and return the last item "green"

From the above two sets of examples, we can clearly see the use of these two sets of methods.

In the JavaScript array, the SHIFT () and push (), Unshift (), and Pop () action methods use the