The function returns a new thing with properties that pass the test.

This function does not generate an event.




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

Explanation of the callback argument:

Iterable Arguments Description
thing name, value Iterate over the thing properties. Both name and value are optional.

Return value

A new thing with the properties that pass the test. If no properties pass the test, a empty thing will be returned.


This code shows an example using filter():

user = {name: 'Iris', age: 6};

 * Return a thing with only property age

user.filter(|prop| prop == 'age');

Return value in JSON format

    "age": 6