title: ngClass for multiple css styles condition
body: <p><strong>HTML</strong></p>
  
  <pre><code>    &lt;span [ngClass]="{
                         'fas fa-star' : isSelected,
                         'far fa-star' : !isSelected
                       }"
            (click)="OnClick()"&gt;
      &lt;/span&gt;
  </code></pre>
  
  <p><strong>typescript</strong></p>
  
  <pre><code>import { Component, OnInit, Input, Output, EventEmitter } from '@angular/core';
  
  
  @Component({
    selector: 'app-one-component',
    templateUrl: './one-component.component.html',
    styleUrls: ['./one-component.component.css']
  })
  export class OneComponentComponent implements OnInit {
  
  @Input() isSelected : boolean;
  @Output() change = new EventEmitter();
    constructor() { }
  
    ngOnInit() {
    }
    OnClick(){
      this.isSelected= !this.isSelected;
      this.change.emit(this.isSelected);
    }
  
  }
  </code></pre>
  
  <p>while clicking icon partial class were loaded like fas or far after space no class was added.</p>