Angular 2: pipes - How to format a phone number?

Question

I've searched here and there, and I am not able to find something specific about formatting a phone number.

Currently, I am retrieving phone numbers form a JSON in the following format:

25565115

However, I want to achieve this result:

02-55-65-115

For that, I believe that I need to use a custom pipe and I don't think that there is a built-in one that does it automatically.

Can you please give me some guidance on how to do so?

Answer 1

StackBlitz

pipe implementation in TS would look like this

import { Pipe } from "@angular/core";  @Pipe({   name: "phone" }) export class PhonePipe {   transform(rawNum) {     rawNum = rawNum.charAt(0) != 0 ? "0" + rawNum : "" + rawNum;      let newStr = "";     let i = 0;      for (; i < Math.floor(rawNum.length / 2) - 1; i++) {       newStr = newStr + rawNum.substr(i * 2, 2) + "-";     }      return newStr + rawNum.substr(i * 2);   } } 

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Declare the PhonePipe in your NgModule's declarations

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Usage:

import {Component} from 'angular/core';  @Component({   selector: "my-app",   template: `     Your Phone Number: <input [(ngModel)]="myNumber" />     <p>       Formatted Phone Number: <b>{{ myNumber | phone }}</b>     </p>   ` }) export class AppComponent {   myNumber = "25565115"; } 

There are many things that can be improved, I just made it work for this particular case.