Anugular JS syllabus

Two-way data binding means that any changes to the UI are immediately reflected in the underlying data model, and any changes to the data model are immediately reflected in the UI. This helps in creating dynamic applications with real-time updates without requiring manual DOM manipulation.

Directives are special markers on DOM elements (like attributes, elements, or CSS classes) that tell AngularJS to attach a specific behavior to that element or even transform the element and its children. Examples include ng-model, ng-repeat, and ng-if.

A scope in AngularJS is an object that refers to the application model. It acts as a glue between the controller and the view. Scopes are hierarchical and can be nested, allowing for a structured and maintainable codebase.

$scope is a service provided by AngularJS that refers to the scope object, which is used for data binding between the controller and the view. scope, on the other hand, is usually a reference to a particular instance of a scope object.

Services in AngularJS are singleton objects that are used to organize and share code across an application. Services can be used to perform common tasks such as logging, data sharing, or server communication. They are injected into controllers, directives, and other services using dependency injection.

Controllers in AngularJS are JavaScript functions that provide data and behavior to the HTML UI. They are responsible for setting up the initial state of the scope object and adding behaviors to it. Controllers do not manipulate the DOM directly but instead focus on managing the scope.

$watch is a method in AngularJS that allows you to observe and act upon changes to scope variables. When the watched variable changes, a callback function is triggered. It is commonly used to monitor changes in data and respond accordingly in the application.

ng-if adds or removes elements from the DOM based on a condition, while ng-show and ng-hide only toggle the visibility of an element using CSS without removing it from the DOM. ng-if is better for performance when you need to completely remove elements, whereas ng-show/ng-hide is useful for toggling visibility without re-rendering.

The digest cycle is a loop that checks for changes in the scope and updates the DOM if needed. During the digest cycle, AngularJS checks all the watched variables, and if any of them have changed, it re-runs the cycle until there are no more changes detected. This process ensures that the UI is always in sync with the data model.