AngularJS modules are containers for different parts of an application, such as controllers, services, directives, filters, etc. They help organize and modularize the codebase, making it easier to manage and maintain.
To create a module, you can use the `angular.module` function:
javascript
var myApp = angular.module(‘myApp’, []);
The first argument is the name of the module, and the second argument is an array of dependencies. In this case, we don’t have any dependencies, so we pass an empty array.
To add components to the module, you can use the `controller`, `service`, `directive`, `filter`, etc. methods of the module object:
javascript
myApp.controller(‘myController’, function($scope) {
// controller logic here
});
myApp.service(‘myService’, function() {
// service logic here
});
myApp.directive(‘myDirective’, function() {
// directive logic here
});
myApp.filter(‘myFilter’, function() {
// filter logic here
});
In the above example, we added a controller, service, directive, and filter to the `myApp` module.
Dependency injection is a design pattern used in AngularJS to make components more modular and reusable. It allows you to inject dependencies into components instead of creating them inside the component itself.
To inject dependencies into a component, you can simply list them as arguments in the component’s function:
javascript
myApp.controller(‘myController’, function($scope, myService) {
// controller logic here
});
In this example, we injected the `$scope` and `myService` dependencies into the `myController` controller.
AngularJS uses a built-in dependency injection system to resolve and provide the dependencies. It automatically creates instances of the dependencies and passes them to the components when they are instantiated.
By using modules and dependency injection, you can create more modular and reusable code, as well as easily manage and test your application components.