JavaScript TypedArray copyWithin() Method

The copyWithin() method copies the sequence of array within the array and set a new starting point at target. The copyWithin() method is a mutable method and update the array directly. It does not alter the length of array, but will change its content and create new properties if necessary. This method have three parameters, two mandatory and one optional.

Syntax:

arr.copyWithin(target)
arr.copyWithin(target, start)
arr.copyWithin(target,start,end)

Parameters:

Target: The index position to copy the elements to. (Required).

Start: The index position elements are started copying from. (Optional)

End: It is optional. Source end index position where to end copying elements from.

Return value:

The modified array.

Browser Support:

Chrome	45.0
Edge	12.0
Firefox	32.0
Opera	NO

Example 1

JavaScript TypedArray copyWithin(target) Method

<script type="text/javascript">
 // Input array  
// JavaScript to illustrate copyWithin() method  
          var arr1= [1,2,3,4,5,6,7,8,9,10]; 
	   arr1.copyWithin(2)
//Placing from index position 2
//The element from index 0

           document.write(arr1);
// expected output: arr1 [Output:1,2,1,2,3,4,5,6,7,8]   
</script> 

Test it Now

Output:

1,2,1,2,3,4,5,6,7,8

Example 2

JavaScript TypedArray copyWithin(target,start) Method

<script type="text/javascript">
// Input array 
// JavaScript to illustrate copyWithin() method    
 var arr1= [1,2,3,4,5,6,7,8,9,10]; 
	   arr1.copyWithin(2,3)
//Placing from index  position  2
// Element from index 3

        document.write(arr1);
// expected output: arr1 [Output: 1,2,4,5,6,7,8,9,10,10]    
</script> 

Test it Now

Output:

1,2,4,5,6,7,8,9,10,10

Example 3

JavaScript TypedArray copyWithin(target,start,end ) Method

<script type="text/javascript">
     // Input array
// JavaScript to illustrate copyWithin() method
  var arr1= [1,2,3,4,5,6,7,8,9,10]; 
  arr1.copyWithin(1,2,4)
// Placing at index position 1      
// Element between index 2 and 4

   document.write(arr1);
// expected output: arr1 [Output: 1,3,4,4,5,6,7,8,9,10]    
</script> 

Test it Now

Output: