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Angular Ng Class If Else

Angular is a powerful front-end framework that offers a variety of features to help developers build dynamic and interactive web applications. One commonly used feature is *ngClass, which allows us to dynamically add or remove CSS classes to HTML elements based on certain conditions. In this article, we'll explore how to use *ngClass in Angular to implement an if-else logic for applying different styles to elements.

To start off, let's dive into the syntax of using *ngClass with if-else conditions. The basic structure looks like this:

Plaintext

<div></div>

In the above example, we have a

element with *ngClass directive. We provide an object where the keys represent the CSS classes we want to apply, and the values are the conditions that determine whether to add the class or not.

Now, let's see this in action with a practical example. Imagine we have a navigation bar and we want to change its background color based on whether the user is logged in or not. We can achieve this using *ngClass with if-else logic in Angular.

First, let's define our component class and template:

Typescript

export class NavbarComponent {
  isLoggedIn: boolean = false;
}

Html

<nav>
  <!-- Navigation links here -->
</nav>

In the above code snippet, we have a boolean variable `isLoggedIn` that determines whether the user is logged in or not. The navigation bar's background color will change dynamically based on this variable. If `isLoggedIn` is true, the 'logged-in' class will be applied, and if it's false, the 'logged-out' class will be applied.

Remember, you can have multiple conditions within *ngClass. Let's extend our example to show how you can add more complex if-else logic:

Html

<nav>
  <!-- Navigation links here -->
</nav>

In this updated example, we added an `isAdmin` boolean variable to differentiate between an admin user and a regular user. Based on the combined conditions, different CSS classes will be applied dynamically to the navigation bar.

Using *ngClass with if-else logic provides a flexible way to manage styles in your Angular applications based on dynamic conditions. It helps in keeping your code clean and readable by eliminating the need for extensive style manipulation within your component logic.

In conclusion, mastering the usage of *ngClass with if-else conditions in Angular can significantly enhance the visual appeal and interactivity of your web applications. Experiment with different scenarios and conditions to leverage this feature effectively in your projects. Happy coding!

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