Using extensions

Extensions allow you to add methods and properties to existing classes, without modifying the original class.

With extensions, you extend the functionality of classes, and this is especially useful when you extend classes that you cannot modify.

Getting ready

To follow along with this recipe, you can write the code in DartPad.

How to do it...

To create a new method that extends the String class, follow these steps:

1. Create an extension called StringExtensions for the String class that adds a method called toBool, which returns false when the string is empty, and true when it’s not:

   extension StringExtensions on String {
     bool toBool() {
       return isNotEmpty;
     }
   }
   

2. Create a method that calls the toBool() method on two strings, one empty and another with some content:

   void testExtension() {
     String emptyString = "";
     String nonEmptyString = "Hello Extensions!";
     print(emptyString...