How to Remove Objects from a JavaScript Associative Array

JavaScript objects can be treated as associative arrays mapping keys to values. To remove a key from an object in JavaScript you can use the delete operator:

Javascript remove a key from an object

When the delete operator is applied to an index property of an Array, you will create a sparsely populated array, which is an array with a missing index.

When working with instances of Array, if you do not want to create a sparsely populated array, then you can use the Array#splice or Array#filter methods.

Associative Arrays

Arrays that have named indexes are called associative arrays. In JavaScript, arrays always use numbered indexes. Associative arrays are object literals.

The delete Operator

The delete operator is used to remove a key from an object. It returns true if the property was successfully deleted or if it does not exist. It returns false only if the property is non-configurable.