In AngularJS, $scope acts as a mediator between the controller and the view, facilitating data binding. It holds the data that is bound to the view and allows the controller to communicate changes to the view and vice versa. $scope is an essential part of the AngularJS digest cycle, ensuring that changes in the model are reflected in the view and vice versa. Understanding the role of $scope is crucial for effective data binding in AngularJS controllers.

The $digest method of the $scope object is used to manually initiate a digest cycle in AngularJS. The digest cycle is a mechanism in AngularJS that checks for changes in the model and updates the view accordingly. By calling $digest, you can trigger this process manually, ensuring that the view reflects the latest changes in the model. Understanding the digest cycle is crucial for handling data binding and updating the UI in AngularJS applications.

Dependency injection in AngularJS plays a crucial role in managing and injecting dependencies into components. It allows components, such as controllers and services, to be loosely coupled and promotes modularity and testability. By injecting dependencies rather than hardcoding them, AngularJS facilitates code maintenance and enhances the flexibility of the application's architecture. Understanding dependency injection is fundamental for effective component interaction in AngularJS.

In AngularJS, the ng-click directive is commonly used to handle DOM events in controllers. The ng-click directive allows you to specify a function in the controller that should be executed when a particular DOM element is clicked. This directive simplifies the process of attaching event handlers to HTML elements, making it easier to handle user interactions in AngularJS applications.

Directives in AngularJS are crucial for separating the view logic from the DOM manipulation code. Directives extend HTML with custom attributes and elements, allowing you to create reusable components and encapsulate view-related behavior. They play a key role in enhancing code modularity and maintainability in AngularJS applications. A solid understanding of directives is essential for developers working with complex and dynamic user interfaces.

AngularJS expressions are case-sensitive and support filters using the Dollar symbol ($). In AngularJS, the expressions are evaluated against the scope, and the Dollar symbol is used to denote built-in objects and services. Understanding the case sensitivity and filter syntax is crucial for writing effective and accurate expressions in AngularJS.

When an AngularJS expression contains a syntax error, the application throws an error, and the entire page may crash. It is important to handle and fix syntax errors promptly to ensure the smooth functioning of the AngularJS application. Proper error handling is crucial for debugging and maintaining code integrity.

In React, props (short for "properties") are a component's input data that are passed down from a parent component. Props are read-only and cannot be changed by the child component. Props are used to customize the behavior and appearance of a component.

React has several major features, including a virtual DOM, server-side rendering, and component reusability. The virtual DOM helps improve performance by minimizing the number of updates needed to the actual DOM. Server-side rendering allows React to render components on the server before sending them to the client, improving performance and SEO. Component reusability allows developers to create reusable UI components using JavaScript. One-way data binding is not a major feature of React.

React Hooks were introduced to provide an alternative way of managing state and lifecycle methods in functional components. However, class components are still fully supported in React, and you can continue to use them if they are working for your project.