How to Quickly Swap Two Variables in JavaScript

Tari Ibaba
Last updated on August 20, 2022
How to Quickly Swap Two Variables in JavaScript

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1. Temporary Variable

To swap two variables in JavaScript:

  1. Create a temporary variable to store the value of the first variable
  2. Set the first element to the value of the second variable.
  3. Set the second variable to the value in the temporary variable.

For example:

let a = 1;
let b = 4;

// Swap variables
let temp = a;
a = b;
b = temp;

console.log(a); // 4
console.log(b); // 1

2. Array Destructuring Assignment

In ES6+ JavaScript we can swap two variables with this method:

  1. Create a new array, containing both variables in a particular order.
  2. Use the JavaScript array destructing syntax to unpack the values from the array into a new array that contains both variables in a reversed order.

With this method, we can create a concise one-liner to do the job.

let a = 1;
let b = 4;

[a, b] = [b, a];

console.log(a); // 4
console.log(b); // 1

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See also