Warmup - Array Filter

The Javascript Array Filter function is used to remove unwanted elements from an array. The filter function accepts a callback function. The callback function is invoked once with each element in the array. If the callback function returns a truthy value the element stays. If the callback function returns a

$http in Angular

$http is an Angular service that make HTTP requests easy and convenient. $http is a wrapper for the XMLHttpRequest and JSONP browser functionality. It is quite similar to jQuery's ajax implementation, so you should have no trouble learning it. $http (and most other Angular built-in services, in fact) uses promises,