How to swap variables using destructuring assignment in JavaScript ?

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Destructuring assignment is a feature introduces in EcmaScript2015 which lets you extract the contents of array, properties of object into distinct variables without writing repetitive code.

Example 1: Here in this example we declared two variables a and b unassigned and an array with two strings “First” and “Second” int it. On line 5 we used destructuring assignment to assign values of array to and b respectively.

Javascript

<script> 
  let a; 
  let b; 
  let array = ["First", "Second"]; 
  
  [a, b] = array; 
  console.log("a:", a); 
  console.log("b:", b); 
</script>

Output:

a: First 
b: Second

As you can see variable a has string “First” assigned and variable b has string “Second” assigned.

Example 2: Here we declared two variables a and b having values “First” and “Second” respectively. In the next line we swapped variables using destructuring assignment.

Javascript

<script> 
  let a = "First"; 
  let b = "Second"; 
  [a, b] = [b, a]; 
  
  console.log("a:", a); 
  console.log("b:", b); 
</script>

Output:

a: Second
b: First

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