How to Clear an Array in JavaScript
Jan 18, 2022
Clearing an array in JavaScript means removing all the elements in the array and leaving an empty array. Here's 3 ways to clear out an array:
array.length = 0
The simplest solution is to assign the array's length to the value of 0.
The array length property is writable.
let array = [1, 2, 3, 4, 5];
array.length = 0;
array; // []array.splice(0, array.length)
A more verbose approach is to use the splice() method.
This function will return a copy of the array before deleting the entries, which is helpful if you want to do a reassignment before clearing the array.
let array = [1, 2, 3, 4, 5];
let anotherArray = array.splice(0, array.length);
anotherArray; // [1, 2, 3, 4, 5]
array; // []
anotherArray === array; // falsearray = []
If you want to avoid mutating the arrays in place for immutability, you can overwrite the array with an empty array [].
let obj = { array: [1, 2, 3, 4, 5] };
obj = { ...obj, array: [] };
obj.array.length; // 0