How do I empty an array in JavaScript?

Emptying an array in JavaScript is a common task when you want to remove all elements without creating a new array. But how do you do this effectively? There are several ways to empty an array, each with its own use case depending on whether you want to preserve references or simply reset the array.

Common methods to empty an array:

1. Setting the length to zero

  array.length = 0;

This is one of the fastest and most memory-efficient ways to clear an array. It modifies the existing array in place and removes all its elements. This method is great if other references point to the same array since it clears them too.

1. Assigning a new empty array

  array = [];

This creates a new empty array and assigns it to the variable. It’s simple but only works if no other references to the original array exist. If other parts of your code hold references, they won’t see the array as empty.

Using splice method

  array.splice(0, array.length);

This removes all elements starting from index 0, effectively emptying the array in place. Like setting length to zero, this also affects all references to the same array.

When to use which method?

• Use array.length = 0 or splice() when you want to clear the array without losing references.
  
• Use array = [] if you want to reset the variable but don’t care about other references.
  

Summary:

• JavaScript offers multiple ways to empty arrays.
  
• Setting length = 0 is the quickest and safest for shared references.
  
• Choose the method depending on whether you want to preserve the original array reference or not.