[Pipe] 콤마처리

https://angular.io/api/common/DecimalPipe

@Component({
  selector: 'number-pipe',
  template: `<div>
    <!--output '2.718'-->
    <p>e (no formatting): {{e | number}}</p>
    
    <!--output '002.71828'-->
    <p>e (3.1-5): {{e | number:'3.1-5'}}</p>
 
    <!--output '0,002.71828'-->
    <p>e (4.5-5): {{e | number:'4.5-5'}}</p>
    
    <!--output '0 002,71828'-->
    <p>e (french): {{e | number:'4.5-5':'fr'}}</p>
 
    <!--output '3.14'-->
    <p>pi (no formatting): {{pi | number}}</p>
    
    <!--output '003.14'-->
    <p>pi (3.1-5): {{pi | number:'3.1-5'}}</p>
 
    <!--output '003.14000'-->
    <p>pi (3.5-5): {{pi | number:'3.5-5'}}</p>
  </div>`
})
export class NumberPipeComponent {
  pi: number = 3.14;
  e: number = 2.718281828459045;
}