Angular *ngSwitchCase Directive

The *ngSwitchCase directive is used to add conditions to an element without the overhead of using nested if statements. It works typically in combination with the *ngSwitch directive.

Syntax

<div [ngSwitch]="variable">
  <div *ngSwitchCase="value1">Content1</div>
  <div *ngSwitchCase="value2">Content2</div>
  <div *ngSwitchDefault>Default content</div>
</div>

Example

<div [ngSwitch]="fruit">
  <div *ngSwitchCase="'apple'">This fruit is red.</div>
  <div *ngSwitchCase="'banana'">This fruit is yellow.</div>
  <div *ngSwitchCase="'kiwi'">This fruit is green.</div>
  <div *ngSwitchDefault>This fruit color is unknown.</div>
</div>

Output

The output of the above example will be:

This fruit is yellow.

Explanation

The *ngSwitchCase directive is used to add a specific case to an element. It matches the value of the *ngSwitch directive. If the value matches, the corresponding case is rendered; otherwise, nothing happens. Additionally, the *ngSwitchDefault directive can be used as a catch-all case when none of the specified *ngSwitchCase values match.

Use

The *ngSwitchCase directive is often used in conjunction with the *ngSwitch directive for conditions based on a single variable. It allows for more concise code than using multiple *ngIf statements.

Important Points

• The *ngSwitchCase directive is used to define a specific case to be matched against the *ngSwitch variable.
• *ngSwitch itself is a directive that specifies the variable to be compared with *ngSwitchCase.
• The *ngSwitchDefault directive is optional and is used as a catch-all for when no *ngSwitchCase values match.
• The *ngSwitchCase values can be of any type that can be used in a comparison with the *ngSwitch variable.

Summary

The *ngSwitchCase directive is a useful feature in Angular that simplifies the process of adding conditions to elements based on a particular variable. It works seamlessly with the *ngSwitch directive and allows for concise code and easy-to-read templates. Understanding its syntax, use cases, and important points will improve your ability to develop efficient and maintainable applications in Angular.