Dart Number: Double Extension

In Dart, extending the built-in double type directly isn't possible.

Here's why:

• Primitive type: double is a primitive type in Dart. Unlike classes, primitive types cannot be subclassed or extended.

Here's what you can do achieve similar functionality:

1. Extension methods:

   • While directly extending double isn't possible, you can achieve similar behavior using extension methods. Extensions allow adding methods to existing classes without modifying the original class.

Example:

Dart

    extension NumberRounding on num {
      // Rounds the number to a specified precision after the decimal point
      num toPrecision(int precision) {
        return num.parse((this).toStringAsFixed(precision));
      }
    }

    // Usage
    double value = 3.14159;
    double roundedValue = value.toPrecision(2); // 3.14

2. Custom classes:

   • If you need more complex functionality beyond simple methods, create a custom class that wraps the double value and provides the desired behavior.

Example:

Dart

    class MyDouble {
      final double value;

      MyDouble(this.value);

      // Add custom methods here
      double getArea() {
        // Implement area calculation based on the value
        return value * value;
      }
    }

    // Usage
    MyDouble areaCalculator = MyDouble(5.0);
    double area = areaCalculator.getArea(); // 25.0

Remember, extensions are generally preferred for adding simple methods to existing types, while custom classes are more suitable for complex functionalities.

For more information, refer to the official Dart documentation on:

• Extension methods: https://dart.dev/language/extension-methods

• Numbers in Dart: https://dart.dev/guides/language/numbers