Angular 14 Built in Pipes Example to Format Text,Date & Currency & Create Custom Pipes in TypeScript

Welcome folks today in this blog post we will be looking the examples of the built in angular pipes to format the data such as text,date and currencyin typescript in browser. All the full source code of the application is shown below.

Get Started

In order to get started you need to make a new angular project using the below command as shown below

ng new sampleproject

cd sampleproject

And after that you will see the below directory structure of the angular app as shown below

And now we need to write the code inside the app.component.ts file as shown below.

app.component.ts

import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css'],
})
export class AppComponent {
  today = new Date();
  cost = 19.99;
  name = 'John Doe';
  percentage = 0.1234;
  description = 'This is a description of something';
}

import { Component } from '@angular/core';

@Component({

selector: 'app-root',

templateUrl: './app.component.html',

styleUrls: ['./app.component.css'],

})

export class AppComponent {

today = new Date();

cost = 19.99;

name = 'John Doe';

percentage = 0.1234;

description = 'This is a description of something';

}

As you can see we have declared the variables for the data that we will be showing inside the html template with built in pipes of angular. We have the date and currency and then we have some text string values as well.

And now we need to copy paste the below code inside the app.component.html file as shown below

<!-- Display the current date using the DatePipe -->
<p>Today's date: {{ today | date }}</p>

<!-- Format a number as a currency using the CurrencyPipe -->
<p>Total cost: {{ cost | currency }}</p>

<!-- Transform a string to uppercase using the UppercasePipe -->
<p>Name: {{ name | uppercase }}</p>

<!-- Format a number with a fixed number of decimal places using the DecimalPipe -->
<p>Percentage: {{ percentage | number:'1.2-2' }}</p>

<!-- Limit the length of a string using the SlicePipe -->
<p>Description: {{ description | slice:0:20 }}...</p>

Today's date: {{ today | date }}

Total cost: {{ cost | currency }}

Name: {{ name | uppercase }}

Percentage: {{ percentage | number:'1.2-2' }}

Description: {{ description | slice:0:20 }}...

As you can see in the above code we are using the interpolation expression to render the values and inside it we are providing the pipes that angular have to format the data such as formatting the date and the currency and we have also pipes to uppercase and lowercase the string values. And lastly for decimal values and to slice the long description.

Creating Custom Pipes

You can execute the below command to generate the custompipe as shown below

ng g pipe custompipe

Here custompipe is the name of the pipe. You can replace it with your own name of the pipe.

After this command two files will be created for the pipe as shown below

And now you need to go to custompipe.pipe.ts file and copy paste the following code

custompipe.pipe.ts

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

@Pipe({
  name: 'custompipe'
})
export class CustompipePipe implements PipeTransform {

  transform(value: number): number {
    return (value*value);
  }

}

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

@Pipe({

name: 'custompipe'

})

export class CustompipePipe implements PipeTransform {

transform(value: number): number {

return (value*value);

}

As you can see in the above typescript code we are simply taking the input value and then transforming it by calculating the square of the number and then returning it.

And now to use this custompipe inside your app.component.html file you can copy paste the following code

app.component.html

In the template, use the pipe by adding a “|” character followed by the pipe name:

<p>{{ 5 | custompipe }}</p>

1	<p>{{ 5 \| custompipe }}</p>