The function returns a new list with items that pass the test.

This function does not generate a change.




Argument Type Description
callback closure (required) Closure to execute on each value.

Explanation of the callback argument:

Iterable Arguments Description
array item, index Iterate over all items in the array. Both item and index are optional.

Return value

A new list with the items that pass the test. If no items passed the test, an empty list will be returned.


This code shows an example using filter():

users = [{name: 'Iris', age: 6}, {name: 'Sasha', age: 34}];

 * Return all users with age 18 or above

users.filter(|user| user.age >= 18);

Return value in JSON format

        "age": 34,
        "name": "Sasha"