JavaScript: Reverse an array

Data manipulation is at the core of any programming language. JavaScript is no exception, especially with JSON taking over as the primary data delivery format. One such data manipulation is array inversion. You can reverse the array to see the most recent transactions or simply sort alphabetically.

Inverting an array in JavaScript was originally done in the following way: reverse But it changes the original array:

// First value:
const arr = ['hi', 'low', 'ahhh'];

// Reverse it without reassigning:
arr.reverse();

// Value:
arr (3) ['ahhh', 'low', 'hi']

Modifying the original array is the traditional method. To avoid this mutation, copy the array and then invert it.

const reversed = [...arr].reverse();

Recently it has become available toReversed To avoid modifying the original array:

const arr = ['hi', 'low', 'ahhh'];
const reversed = arr.toReversed(); // (3) ['ahhh', 'low', 'hi'];
arr; // ['hi', 'low', 'ahhh']

Avoiding data object mutations is very important in programming languages ​​like JavaScript, where object references are important.