The filter Filter
The AngularJS "filter" filter is used to select a subset of an array and returns it as a new array. The "filter" filter can only be used on array, and it returns an array containing only the matching items.
array: It specifies the source array.
expression: It may be string, object or function. It is used to select items from the array for matching.
comparator: It is used to compare the expected value from the filter expression and actual value from the object in the array.
anyPropertyKey: It is a special property name that matches against any property. It is optional. By default, it is $.
Let's take an example to demonstrate "filter" filter.
See this example:Test it Now
Note: This example returns an array containing the letter "a" because filter is used on letter "a".