What is ngSwitch in angular?

In Angular 8, ngSwitch is a structural directive which is used to Add/Remove DOM Element. It is similar to switch statement of C#. The ngSwitch directive is applied to the container element with a switch expression.

What is the function of ngSwitch in angular?

NgSwitchlink The [ngSwitch] directive on a container specifies an expression to match against. The expressions to match are provided by ngSwitchCase directives on views within the container. Every view that matches is rendered. If there are no matches, a view with the ngSwitchDefault directive is rendered.

What is difference between ng template and Ng container?

To sum up, ng-content is used to display children in a template, ng-container is used as a non-rendered container to avoid having to add a span or a div , and ng-template allows you to group some content that is not rendered directly but can be used in other places of your template or you code.

What is ngIf and ngFor in angular?

Directives preceded with a * like *ngIf , *ngFor , and *ngSwitchCase are structural directives. Structural directives modify the DOM by adding or removing certain elements. If an element is removed, it is completely removed rather than just being hidden.

What is * in * ngIf in Angular?

The ngIf Directive + else According to the Angular API, the ngIf directive is a structural directive that conditionally includes a template based on the value of an expression coerced to Boolean.

What is NG if in Angular?

Overview. The ngIf directive removes or recreates a portion of the DOM tree based on an {expression}. If the expression assigned to ngIf evaluates to a false value then the element is removed from the DOM, otherwise a clone of the element is reinserted into the DOM.

Where are ng templates used?

ng-template is a virtual element and its contents are displayed only when needed (based on conditions). ng-template should be used along with structural directives like [ngIf],[ngFor],[NgSwitch] or custom structural directives. That is why in the above example the contents of ng-template are not displayed.

Can we have ng-container inside ng-template?

Also, multiple structural directives are not possible inside ng-template but ng-container can be used to wrap multiple elements containing different structural directives so it is a perfect container.

What is * ngIf?

The NgIf directive is used when you want to display or remove an element based on a condition. We define the condition by passing an expression to the directive which is evaluated in the context of it’s host component. The syntax is: *ngIf=”condition” See the documentation: https://angular.io/api/common/NgIf.

What is TemplateRef in Angular?

TemplateRef is a class and the way to reference the ng-template in the component or directive class. Using the TemplateRef we can manipulate the template from component code.

What is * NgFor?

*ngFor is a predefined directive in Angular. It accepts an array to iterate data over atemplate to replicate the template with different data. It’s the same as the forEach() method in JavaScript, which also iterates over an array.

What is Dom in Angular?

The Document Object Model (DOM) is an application programming interface (API) for HTML and XML documents. It defines the logical structure of documents and the way a document is accessed and manipulated.