How to Reverse Array in JavaScript: Simple Guide

To reverse an array in JavaScript, use the reverse() method which reverses the elements in place. For example, array.reverse() changes the original array order to the opposite.

Syntax

The reverse() method is called on an array and reverses its elements in place, returning the same array but with elements in reverse order.

• array.reverse(): Reverses the array elements.

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array.reverse()

Example

This example shows how to reverse an array of numbers using reverse(). The original array is changed after calling the method.

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const numbers = [1, 2, 3, 4, 5];
numbers.reverse();
console.log(numbers);

Output

[5, 4, 3, 2, 1]

Common Pitfalls

A common mistake is expecting reverse() to return a new reversed array without changing the original. It actually reverses the original array in place.

If you want to keep the original array unchanged, create a copy first using slice() or spread syntax.

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const original = [1, 2, 3];
const reversedWrong = original.reverse();
console.log(original); // [3, 2, 1] - original changed

// Correct way to keep original unchanged
const original2 = [1, 2, 3];
const reversedCopy = [...original2].reverse();
console.log(original2); // [1, 2, 3] - original unchanged
console.log(reversedCopy); // [3, 2, 1]

Output

[3, 2, 1]
[1, 2, 3]
[3, 2, 1]

Quick Reference

Remember these tips when reversing arrays in JavaScript:

• reverse() changes the original array.
• Use [...array] or array.slice() to copy before reversing if needed.
• Works on arrays of any type (numbers, strings, objects).

Key Takeaways

Use array.reverse() to reverse an array in place in JavaScript.

reverse() modifies the original array, not a copy.

Create a copy with [...array] or slice() before reversing to keep the original unchanged.

The method works on arrays containing any data type.

Always check if you want to mutate the original array before using reverse().