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API > @angular/core

PipeTransform

To create a Pipe, you must implement this interface.

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      interface PipeTransform {
  transform(value: any, ...args: any[]): any
}

Class implementations

Description

Angular invokes the transform method with the value of a binding as the first argument, and any parameters as the second argument in list form.

Methods

transform()

transform(value: any, ...args: any[]): any
      
      transform(value: any, ...args: any[]): any

Parameters

value

Type: any.
args

Type: any[].

Returns

any

Usage notes

Example

The RepeatPipe below repeats the value as many times as indicated by the first argument:

import {Pipe, PipeTransform} from '@angular/core'; @Pipe({name: 'repeat'}) export class RepeatPipe implements PipeTransform { transform(value: any, times: number) { return value.repeat(times); } } 
      
      import {Pipe, PipeTransform} from '@angular/core';

@Pipe({name: 'repeat'})
export class RepeatPipe implements PipeTransform {
  transform(value: any, times: number) {
    return value.repeat(times);
  }
}

Invoking {{ 'ok' | repeat:3 }} in a template produces okokok.