OrderBy Pipe is not Working on array of objects in angular 4?

I have a array of objects and i want to sort them according to size which is a attribute of the object . Object consists of {name , size}.i want to sort the elements according to size.

service:

search(term: string): Observable<Array<Object>> {
  let apiURL = `${this.apiRoot}?search=${term}`;
  return this.http.get(apiURL)
           .map(res => {
             return res.json().results.map(items => {
               return {name: items.name, population: items.population};
             });
           });
}

component:

 ngOnInit() { 
  this.myshared.getSaveBtnStatus().subscribe(data => this.isSuccess = data);
    this.searchField = new FormControl();
    this.searchField.valueChanges
    .debounceTime(400)
    .distinctUntilChanged()
    .switchMap(term => this.myservice.search(term))
    .subscribe(value => {
      this.results = value;
      console.log(this.results);
    }
    );

HTML:

<ul class="list-group">
<li class="list-group-item"  *ngFor="let items of results">
{{items.name | orderBy : ['population'] }}
</li>
</ul>

Angular 2+ doesn't have orderBy pipe. But it is very easy to build one for what you want.

Here is a simple implementation of the pipe to achieve what you want

import { Pipe, PipeTransform } from "@angular/core";

@Pipe({
  name: "orderBy"
})
export class OrderByPipe implements PipeTransform {

  transform(value: any[], property: any, descending?: boolean): any {
    if (!value || value.length) {
      return value;
    }

    value.sort((first: any, second: any): number => {
        return first[property] > second[property] ? 1 : -1;
    });

    if (descending) {
      return value.reverse();
    }

    return value;
  }
}