KeyValuePipe

Transforms Object or Map into an array of key value pairs.

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{{ input_expression | keyvalue [ : compareFn ] }}

NgModule

• CommonModule

Input value

input

{ [key: string]: V; [key: number]: V; } | Map

Parameters

compareFn

(a: KeyValue, b: KeyValue) => number

Optional. Default is defaultComparator.

Description

The output array will be ordered by keys. By default the comparator will be by Unicode point value. You can optionally pass a compareFn if your keys are complex types.

Usage notes

Examples

This examples show how an Object or a Map can be iterated by ngFor with the use of this keyvalue pipe.

@Component({
  selector: 'keyvalue-pipe',
  template: `<span>
    <p>Object</p>
    <div *ngFor="let item of object | keyvalue">
      {{item.key}}:{{item.value}}
    </div>
    <p>Map</p>
    <div *ngFor="let item of map | keyvalue">
      {{item.key}}:{{item.value}}
    </div>
  </span>`
})
export class KeyValuePipeComponent {
  object: {[key: number]: string} = {2: 'foo', 1: 'bar'};
  map = new Map([[2, 'foo'], [1, 'bar']]);
}