What is the role of $scope in data binding within AngularJS controllers?

  • Acts as a mediator between the controller and the view
  • Handles routing in AngularJS applications
  • Manages view-specific data
  • Represents the entire application state
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.

What is the role of $scope in handling events within AngularJS controllers?

  • It controls the event propagation
  • It facilitates two-way data binding
  • It manages the DOM elements
  • It provides a context for variables and functions
In AngularJS, $scope plays a crucial role in handling events within controllers by providing a context for variables and functions. The $scope object is used to establish a link between the controller and the view, enabling two-way data binding. Events triggered in the view can be handled by functions defined on the $scope, allowing for effective communication and interaction in AngularJS applications.

In complex applications, what are the performance considerations for using two-way data binding in AngularJS?

  • Avoiding Deep Nesting
  • Debouncing Input Events
  • Limited Watchers
  • Minimal Scope Variables
In complex applications, performance considerations for using two-way data binding in AngularJS include minimizing the number of watchers. Two-way data binding creates watchers that track changes in the model, and an excessive number of watchers can impact performance. It's important to limit the use of two-way data binding, especially in scenarios where it's not necessary, and optimize the application by reducing the number of watchers. This knowledge is vital for developing scalable and high-performance AngularJS applications.

How does AngularJS ensure security within expressions to prevent XSS attacks?

  • Automatic sanitization of expressions
  • Client-side validation of expressions
  • Restrictive expression syntax
  • Token-based security mechanism
AngularJS ensures security within expressions to prevent XSS attacks by automatically sanitizing expressions. This means that AngularJS escapes potentially dangerous content before rendering it, reducing the risk of executing malicious code. Developers should rely on AngularJS's built-in security measures and adhere to best practices to create robust and secure applications, especially when dealing with user-generated content.

AngularJS expressions are ___________ sensitive and support filters using the ___________ symbol.

  • Case, At
  • Case, Dollar
  • Case, Hash
  • Case, Percent
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.

__________ in AngularJS are crucial for separating the view logic from the DOM manipulation code.

  • Controllers
  • Directives
  • Expressions
  • Services
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.

In AngularJS, which directive is commonly used to handle DOM events in controllers?

  • ng-bind
  • ng-click
  • ng-controller
  • ng-model
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.

What role does dependency injection play in the MVC architecture of AngularJS?

  • It controls the order of function execution in controllers
  • It ensures data consistency in the model
  • It manages and injects dependencies into components
  • It prevents dependency between different components
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.

Should I keep all component's state in Redux store?

  • Yes, it is recommended to keep all component state in the Redux store
  • No, it is recommended to keep only the necessary state in the Redux store
It is not recommended to keep all component state in the Redux store. While Redux is useful for managing state in large applications, it can also add unnecessary complexity and boilerplate code to small applications. It is recommended to keep only the necessary state in the Redux store and use component state for simpler state management needs.

What would be the common mistake of function being called every time the component renders?

  • Declaring the function inside the component's render method
  • Not using React.lazy() to lazy-load the component
  • Not using React.memo() to memoize the component
  • Not using the shouldComponentUpdate() method to prevent unnecessary re-renders
A common mistake that can cause a function to be called every time the component renders is declaring the function inside the component's render method. This can cause the function to be recreated every time the component renders, even if the function's dependencies have not changed. To avoid this problem, functions should be declared outside the render method, or in a separate file if they are reused across multiple components.

What is the difference between React and ReactDOM?

  • React is a server-side rendering library, while ReactDOM is a client-side rendering library
  • React is for creating components, while ReactDOM is for rendering components to the DOM
  • React is for handling state and events, while ReactDOM is for handling rendering and updating
  • There is no difference, they are the same thing
React is a library for creating components and managing the state and events of those components, while ReactDOM is a library for rendering those components to the DOM. React provides the programming interface for working with components, while ReactDOM provides the methods for rendering and updating the components in the browser.

Is it possible to use async/await in plain React?

  • No, async/await is not supported in plain JavaScript
  • No, async/await requires a library or framework like Redux or Apollo
  • Yes, async/await can be used with plain React components
  • Yes, async/await can be used with the "react-async" library
In plain React, you can use async/await to handle asynchronous operations like API calls or Promises. Async/await is a feature of ECMAScript 2017, and can be used with modern browsers or transpiled code. However, you may need to use a library or framework like Redux or Apollo to manage the async state and data flow in your application.