with.a.pipe.ts

@Pipe({
  name: 'slashed'
})
export class Slashed implements PipeTransform {
  transform(value){
    return value.map(item => {
      return {
        label: '/' + item.label,
        value: item.value
      };
    })
  }
}


@Component({
  selector: 'some-component',
  template: `
    <div>
      <dropdown-component [options]="weightUnits"></dropdown-component>
      <input type="text" placeholder="Price">
      <dropdown-component [options]="(weightUnits | slashed)"></dropdown-component>
      <-- This will do the job -->
    </div>
`
})
export class SomeComponent {
  public weightUnits = [{value: 1, label: 'kg'}, {value: 2, label: 'oz'}];
  
  // we will delegate the data transformation to a pipe
}