JavaScript Array shift() Method

Last Updated : 04 Oct, 2021

Below is the example of Array shift() method.

Hey geek! The constant emerging technologies in the world of web development always keeps the excitement for this subject through the roof. But before you tackle the big projects, we suggest you start by learning the basics. Kickstart your web development journey by learning JS concepts with our JavaScript Course. Now at it's lowest price ever!

Example:

<script>
function func() { 
      
    // Original array 
    var array = ["GFG", "Geeks", "for", "Geeks"]; 
  
    // Checking for condition in array 
    var value = array.shift(); 
  
    document.write(value);
    document.write("<br />"); 
    document.write(array); 
} 
  
func();
</script>

Output:
```
GFG
Geeks, for, Geeks
```

The arr.shift() method removes the first element of the array thus reducing the size of the original array by 1.

Syntax:

arr.shift()

Parameters: This method does not accept any parameter.

Return value: This function returns the removed first element of the array. If the array is empty then this function returns undefined.

Note: This function can also be used with other javascript objects that behave like the array.

Below examples illustrate the JavaScript Array shift() method:

Example 1: In this example the shift() method removes the first element of the array, therefore it returns 34.
```
var arr = [2, 5, 8, 1, 4];
document.write(value);
document.write(arr);
```
Output:
```
34
234,567,4
```
Example 2: In this example the shift() method tries to remove the first element of the array, but the array is empty, therefore it returns undefined.
```
var arr = [];
document.write(value);
document.write(arr)
```
Output:
```
undefined
```

Code for the above method is provided below:

Program 1:

<script> 
function func() { 
      
    // Original array 
    var array = [34,234,567,4]; 
  
    // Checking for condition in array 
    var value = array.shift(); 
  
    document.write(value);
    document.write("<br />"); 
    document.write(array); 
} 
  
func(); 
</script> 

Output:

34
234,567,4

Program 2:

<script>
function func() { 
      
    // Original array 
    var array = []; 
  
    // Checking for condition in array 
    var value = array.shift(); 
  
    document.write(value);
    document.write("<br />"); 
    document.write(array); 
} 
  
func();
</script>