There are three structural directives in angular
*ngIf  
[ngSwtich]
*ngFor1. [ngSwtich] condition can be use when you wanted to testfy with mutlple values
In the below example [ngSwitch] directive is added to div and then compare the variable “color” using *ngSwitchCase
import { Component, OnInit } from '@angular/core';  
@Component({
  selector: 'app-test',
  template: `
  <h1> Welcome {{name}} </h1> 
      
    <div [ngSwitch] = "color"> 
       <div  *ngSwitchCase = "'red'"> Red color is selected  </div>
       <div  *ngSwitchCase= "'blue'"> Blue color is selected  </div>
       <div  *ngSwitchCase= "'green'"> Green color is selected  </div>
      <div  *ngSwitchDefault> Please select the color</div>
    </div>
  `,
  styles: [`   `]
})
export class TestComponent implements OnInit {
  public name = "Amey Raut";  
  public color ="red";  
  constructor() { }
  ngOnInit() {
  } 
 
  
}