Definition and Usage

The reverse() function for arrays reverses the order of the elements in the given array.

Features

  • This function modifies the original array in place.
  • The first element of the array becomes the last, and the last element becomes the first.
  • It does not return a new array.

Basic Example

JavaScript 
const arr = [1, 2, 3, 4, 5];
const reversedArr = arr.reverse();

/* Reverses the order of elements in the array */
console.log(reversedArr); // Output: [5, 4, 3, 2, 1]

/* Modifies the original array in place */
console.log(arr); // Output: [5, 4, 3, 2, 1]

Syntax

JavaScript 
arr.reverse()

arr is the array to which the reverse() function is applied.

Parameters

None.

Return value

Reverses the elements of the original array in place and returns the modified array. The return value is the original array itself after modification. It does not return a new array.

Things to Keep in Mind

The reverse() function modifies the original array in place.

That is, calling reverse() reverses the elements of the original array itself. It does not create a new array or a copy. Therefore, you should be aware that the original array will be changed when using this function. If you want to reverse the elements while keeping the original array intact, create a copy of the array before applying reverse(), or use the toReversed() function, which returns a new array with the elements in reverse order without modifying the original array.

Creating a Copy of the Original Array Using slice()

Additional Explanation
The slice() function for arrays extracts a portion of an array based on a specified index range and returns a new array.

JavaScript 
const originalArray = [1, 2, 3, 4, 5];

// Create a copy of the original array
const copiedArray = originalArray.slice();

// Apply the reverse() function to the copy
copiedArray.reverse();

console.log(originalArray); // [1, 2, 3, 4, 5] (the original array remains unchanged)
console.log(copiedArray);   // [5, 4, 3, 2, 1] (the array is reversed)

Creating a Copy of the Original Array Using the Spread (...) Syntax

Additional Explanation
The spread (...) syntax is a JavaScript feature that allows you to expand the elements of an iterable object (such as an array, string, or DOM collection) into individual elements. It is used by placing an iterable object (array, string, DOM collection, etc.) after the ... three dots.

JavaScript 
const originalArray = [1, 2, 3, 4, 5];

// Create a copy of the original array using the spread (...) syntax
const copiedArray = [...originalArray];

// Apply the reverse() function to the copy
copiedArray.reverse();

console.log(originalArray); // [1, 2, 3, 4, 5] (the original array remains unchanged)
console.log(copiedArray);   // [5, 4, 3, 2, 1] (the array is reversed)

Using the toReversed() Function

The toReversed() function works exactly like the reverse() function, but it does not modify the original array.

The toReversed() function was introduced in ECMAScript 2023 to address the limitations of reverse(). Previously, the reverse() function was the only way to reverse the order of elements in an array.

Since reverse() modifies the original array, it cannot be used when you need to preserve the original elements. The toReversed() function creates a new array with the elements reversed, solving this problem.

JavaScript 
const originalArray = [1, 2, 3, 4, 5];

/* Reverses the order of the elements in the array */
const reversedArray = originalArray.toReversed();

console.log(reversedArray); // [5, 4, 3, 2, 1] (the array is reversed)

/* The original array remains unchanged */
console.log(originalArray);   // [1, 2, 3, 4, 5]

Note:
The toReversed() function was introduced in 2023, so you should check browser compatibility before using it.

Compatibility for JavaScript Array toReversed() Function
Method
Desktop Chrome
Chrome
DesktopDesktop Edge
Edge
Desktop Firefox
Firefox
Safari
Safari
Node.js
Node.js
toReversed() 110 110 115 16 20

Practical Examples

The reverse() function can be used in various situations. Let's take a look at a few examples.

Reversing and Iterating

JavaScript 
const numbers = [1, 2, 3, 4, 5];

// Reverse the array order and print each element
numbers.reverse().forEach(number => {
    console.log(number);
});

// Output: 5, 4, 3, 2, 1

Code Explanation
The forEach() function is used to loop through an array and process each element with a callback function.

Reversing a String

JavaScript 
const str = "Hello, World!";

// Convert the string to an array, reverse it, then join it back to a string
const reversedStr = str.split("").reverse().join("");

console.log(reversedStr);
// Output: "!dlroW ,olleH"

Code Explanation
The split() function for strings splits a string into an array based on a given delimiter or regular expression.

Code Explanation
The sort() function for arrays is used to rearrange the elements of an array in a desired order.

Code Explanation
The join() function for arrays joins the elements of an array into a single string, using a specified separator.

Reversing and Filtering

JavaScript 
const numbers = [1, 2, 3, 4, 5];

// Reverse the array and filter out the elements that meet a condition
const filteredNumbers = numbers.reverse().filter(number => number % 2 === 0);

console.log(filteredNumbers);
// Output: [4, 2]

Code Explanation
The filter() function for arrays filters elements of an array using a callback function.

Compatibility

Compatibility for JavaScript Array reverse() Function
Method
Desktop Chrome
Chrome
DesktopDesktop Edge
Edge
Desktop Firefox
Firefox
Safari
Safari
Node.js
Node.js
reverse() 1 12 1 1 0.10

Specifications

Specification for JavaScript Array reverse() Function
Specification
reverse() ECMAScript® 2026 Language Specification
#sec-array.prototype.reverse

References

See also