How to Copy an Array in JavaScript - Step by Step Examples



How to Copy an Array in JavaScript ?

Answer

To copy an array in JavaScript, you can use various methods such as spread operator, Array.from(), or Array.slice().



✐ Examples

1 Copying an Array using Spread Operator

In this example,

  1. We create an array named array1 with elements.
  2. We then use the spread operator [...array1] to create a copy of array1 and store it in array2.
  3. The spread operator creates a new array with the same elements as the original array.

JavaScript Program

const array1 = [1, 2, 3, 4, 5];
const array2 = [...array1];
console.log('Array 1:', array1);
console.log('Array 2 (copy of Array 1):', array2);

Output

Array 1: [ 1, 2, 3, 4, 5 ]
Array 2 (copy of Array 1): [ 1, 2, 3, 4, 5 ]

2 Copying an Array using Array.from()

In this example,

  1. We create an array named array1 with elements.
  2. We then use Array.from(array1) to create a copy of array1 and store it in array2.
  3. Array.from() creates a new array instance from an array-like or iterable object.

JavaScript Program

const array1 = [1, 2, 3, 4, 5];
const array2 = Array.from(array1);
console.log('Array 1:', array1);
console.log('Array 2 (copy of Array 1):', array2);

Output

Array 1: [ 1, 2, 3, 4, 5 ]
Array 2 (copy of Array 1): [ 1, 2, 3, 4, 5 ]

3 Copying an Array using Array.slice()

In this example,

  1. We create an array named array1 with elements.
  2. We then use array1.slice() to create a copy of array1 and store it in array2.
  3. Array.slice() returns a shallow copy of a portion of an array into a new array object.

JavaScript Program

const array1 = [1, 2, 3, 4, 5];
const array2 = array1.slice();
console.log('Array 1:', array1);
console.log('Array 2 (copy of Array 1):', array2);

Output

Array 1: [ 1, 2, 3, 4, 5 ]
Array 2 (copy of Array 1): [ 1, 2, 3, 4, 5 ]

Summary

In this tutorial, we learned How to Copy an Array in JavaScript language with well detailed examples.




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