Angular Pipes

Angular pipes are a feature in Angular that allows you to transform and format data before displaying it in the user interface. Pipes are essentially functions that take an input value and return a transformed output value. They are represented by the | symbol in Angular templates.

Angular provides several built-in pipes that you can use out of the box, as well as the ability to create custom pipes to suit your specific needs.

Here are some commonly used built-in pipes in Angular:

1. {{ value | uppercase }}: Transforms the input value to uppercase.
2. {{ value | lowercase }}: Transforms the input value to lowercase.
3. {{ value | currency }}: Formats the input value as a currency, based on the current locale.
4. {{ value | date }}: Formats the input value as a date, based on the current locale.
5. {{ value | number }}: Formats the input value as a number, based on the current locale.

You can also chain multiple pipes together for more complex transformations. For example:

{{ value | uppercase | slice:0:10 }}

In addition to the built-in pipes, you can create your own custom pipes by implementing the PipeTransform interface. Custom pipes allow you to encapsulate complex transformation logic and reuse it throughout your application.

To use a custom pipe, you need to:

1. Create a class that implements the 'PipeTransform' interface.
2. Define the 'transform' method in your class to perform the desired transformation.
3. Register your custom pipe in the Angular module's 'declarations' array.

Once registered, you can use your custom pipe in your templates by applying the pipe symbol (|) followed by the name of your custom pipe.

Pipes are a powerful tool in Angular for transforming and formatting data in a convenient and reusable way. They help keep your templates clean and concise by separating the data transformation logic from the view layer.