JavaScript Tutorials

JavaScript Array slice()
Syntax & Examples

Array.slice() method

The slice() method of the Array class in JavaScript extracts a section of the calling array and returns a new array.

Syntax of Array.slice()

There are 3 variations for the syntax of Array.slice() method. They are:

1.
slice()

This method extracts a section of the calling array from the beginning and returns a new array.

Returns value of type Array.

2.
slice(start)

Parameters

ParameterOptional/RequiredDescription
startoptionalThe beginning index of the section to extract. Defaults to 0.

This method extracts a section of the calling array from the start index to the end of the array and returns a new array.

Returns value of type Array.

3.
slice(start, end)

Parameters

ParameterOptional/RequiredDescription
startoptionalThe beginning index of the section to extract. Defaults to 0.
endoptionalThe end index of the section to extract. Defaults to the array's length. The end index is not included in the extracted section.

This method extracts a section of the calling array from the start index to the end index (not included) and returns a new array.

Returns value of type Array.


✐ Examples

1 Using slice() method to extract a section of an array

In JavaScript, we can use the slice() method to extract a section of an array and return a new array.

For example,

  1. We define an array variable arr with elements [1, 2, 3, 4, 5].
  2. We use the slice() method on arr with the start index 1 and the end index 3 to extract a section of the array.
  3. The result is stored in the variable slicedArr.
  4. We log slicedArr to the console using console.log() method to see the extracted section of the array.

JavaScript Program

const arr = [1, 2, 3, 4, 5];
const slicedArr = arr.slice(1, 3);
console.log(slicedArr);

Output

[2, 3]

2 Using slice() method to extract from a specific start index to the end of an array

We can use the slice() method to extract a section of an array from a specific start index to the end of the array and return a new array.

For example,

  1. We define an array variable arr with elements ['a', 'b', 'c', 'd', 'e'].
  2. We use the slice() method on arr with the start index 2 to extract a section of the array from index 2 to the end.
  3. The result is stored in the variable slicedArr.
  4. We log slicedArr to the console using console.log() method to see the extracted section of the array.

JavaScript Program

const arr = ['a', 'b', 'c', 'd', 'e'];
const slicedArr = arr.slice(2);
console.log(slicedArr);

Output

['c', 'd', 'e']

3 Using slice() method to make a shallow copy of an array

We can use the slice() method without arguments to make a shallow copy of an array and return a new array.

For example,

  1. We define an array variable arr with elements [10, 20, 30].
  2. We use the slice() method on arr without any arguments to make a shallow copy of the array.
  3. The result is stored in the variable copiedArr.
  4. We log copiedArr to the console using console.log() method to see the shallow copy of the array.

JavaScript Program

const arr = [10, 20, 30];
const copiedArr = arr.slice();
console.log(copiedArr);

Output

[10, 20, 30]

Summary

In this JavaScript tutorial, we learned about slice() method of Array: the syntax and few working examples with output and detailed explanation for each example.