How to filter an array in JavaScript

Published Sep 1 2022

The filter() method in JavaScript iterates through an array, invoking a predicate

function upon each element and returning a new array that contains only those elements for which this function returned a truthy

value. We can think of the predicate as a condition that the element must pass to be included in the new array.

Some examples of when the filter() method is helpful include building an array that contains only truthy values, even numbers or values that are not in another array.

Simple JavaScript array filter examples

Filtering an array of objects

It is a common requirement to filter an array of objects based on a property of the object having a particular value. The filter() method can be used in exactly the same way as it was for the more simple arrays above.

Filtering an array of objects examples

So, just as we use a coffee filter

to remove unwanted sediment from a combination of hot water and ground coffee, the JavaScript filter() method allows us to create a new array from an existing array with the unwanted elements removed.

Far out, right!?