JavaScript typedArray.copyWithin() with Examples
Last Updated :
22 Dec, 2022
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The Javascript typedArray.copyWithin() is an inbuilt function in JavaScript that is used to copy some elements of a typedArray at the specified location in the same typedArray.
Syntax:
typedArray.copyWithin(target, start, end)
Parameters: It accepts three parameters that are specified below-
- target: It is the start index position from where to copy the element.
- start: It is the start index position from where to start copying elements and its default value is starting index of the typedArray.
- end: It is optional and it is the end position index till the elements are to be copied and its default value is the end of the typedArray.
Return value: It returns the modified array after the copying process is done.
JavaScript examples to show the working of this function:
Example 1: This example shows the use of typedArray.copyWithin() function with all parameters.
<script>
// Constructing a new typedArray "A"
// with some elements
const A = new Uint8Array([ 5, 10, 15, 20, 25, 30, 35, 40 ]);
// Calling copyWithin function to copy
// element from index position 0 and
// element from index 4 to 5
A.copyWithin(0, 4, 5);
// Printing a new modified array
console.log(A);
</script>
Output:
25,10,15,20,25,30,35,40
Example 2: This example shows the use of typedArray.copyWithin() function with all parameters.
<script>
// Constructing some new typedArrays
// with some elements
const A = new Uint8Array([ 5, 10, 15, 20, 25, 30, 35, 40 ]);
const B = new Uint8Array([ 5, 10, 15, 20, 25, 30, 35, 40 ]);
const C = new Uint8Array([ 5, 10, 15, 20, 25, 30, 35, 40 ]);
const D = new Uint8Array([ 5, 10, 15, 20, 25, 30, 35, 40 ]);
const E = new Uint8Array([ 5, 10, 15, 20, 25, 30, 35, 40 ]);
// Calling copyWithin function with different
// parameters
a = A.copyWithin(0, 5);
b = B.copyWithin(1, 4);
c = C.copyWithin(0, 4, 5);
d = D.copyWithin(2, 3, 5);
e = E.copyWithin(0, 1, 4);
// Printing new modified arrays
console.log(a);
console.log(b);
console.log(c);
console.log(d);
console.log(e);
</script>
Output:
30,35,40,20,25,30,35,40 5,25,30,35,40,30,35,40 25,10,15,20,25,30,35,40 5,10,20,25,25,30,35,40 10,15,20,20,25,30,35,40
