JavaScript toReversed Function with Examples

JavaScript toReversed returns a new array with the reversed order of its elements. It does not change the original array at any step. This function works in a predictable and simple way for arrays.

Understand the toReversed Function in JavaScript

The toReversed function creates a copy of an array and puts elements in reverse order. It leaves the original array without any change.

The syntax looks like this:

array.toReversed()

It takes no parameters. It returns a new array with elements in reverse order. You write it like this to avoid errors:

const newArray = oldArray.toReversed();

It first copies all elements of the array into a new array. It then places the elements from the last to the first index. The original array stays intact and can still be used.

Here is an example:

const numbers = [1, 2, 3];
const reversed = numbers.toReversed();

This returns the expected value. The result is [3, 2, 1] and the original array [1, 2, 3] stays the same.

The Difference Between toReversed and reverse

The reverse() method changes the array in place and returns it. The toReversed() method returns a new reversed array without changing the original one.

Use toReversed() when you need a reversed copy without change to the source. Use reverse() when you want to reverse the original array itself.

Examples of the toReversed Function in JavaScript

Reverse Numbers Without Changing Original:

const nums = [10, 20, 30];
const copy = nums.toReversed();

This shows it in action clearly. It creates a new array [30, 20, 10] and keeps nums as [10, 20, 30].

Reverse Strings in Array:

const words = ["apple", "banana", "cherry"];
const reversedWords = words.toReversed();

This returns the expected value. It outputs ["cherry", "banana", "apple"] and leaves the original array unchanged.

Compare reverse() and toReversed():

const arr = [1, 2, 3];
const rev1 = arr.reverse();
const rev2 = arr.toReversed();

This shows it in action clearly. The reverse() method changes arr to [3, 2, 1] while toReversed() keeps arr intact and returns [1, 2, 3] reversed separately.

Chain Methods with toReversed():

const values = [5, 10, 15];
const newVals = values.toReversed().map(x => x * 2);

This gives you the result immediately. It first reverses into [15, 10, 5] then maps to [30, 20, 10] without any change to the original array.

Wrapping Up

You learned the meaning of toReversed and the difference from reverse.

Here is a quick recap:

• toReversed makes a reversed copy without change to the source.
• reverse changes the array itself and returns it.

FAQs

let numbers = [1, 2, 3];
let newArray = numbers.toReversed();

console.log(newArray); // [3, 2, 1]
console.log(numbers);  // [1, 2, 3]

let data = [10, 20, 30];
let rev = data.reverse();
console.log(rev);   // [30, 20, 10]
console.log(data);  // [30, 20, 10]

let nums = [10, 20, 30];
let safe = nums.toReversed();
console.log(safe);  // [30, 20, 10]
console.log(nums);  // [10, 20, 30]

let word = "hello";
let reversed = word.split("").toReversed().join("");

console.log(reversed); // "olleh"

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