Late Static Binding

Late static binding (LSB) is a feature primarily associated with dynamically typed languages like PHP. It allows static methods and properties to be resolved at runtime based on the calling class context, rather than the class in which they were defined.

Languages with Late Static Binding

1. PHP:
   • PHP is the most well-known language that supports late static binding using the static keyword.

Languages with Early Static Binding

Early static binding is more common in statically typed languages, where static methods and properties are resolved at compile-time based on the class in which they were defined. This is the behavior seen in Java.

1. Java:

   • In Java, static methods and properties are resolved at compile-time based on the class where they are defined.

2. C#:

   • C# has similar behavior to Java regarding static methods and properties. They are resolved at compile-time based on the class where they are defined.

3. C++:

   • C++ also uses early static binding for static members. The resolution is based on the class in which they are defined.

4. Swift:

   • Swift resolves static members at compile-time based on the defining class.

5. Kotlin:

   • Kotlin, like Java, resolves static members at compile-time. It uses companion objects to simulate static members, but the resolution is similar to early static binding.

6. TypeScript:

   • TypeScript, when compiled to JavaScript, follows JavaScript's behavior for static members, which is early static binding.

Summary

• Languages with Late Static Binding:

  • PHP: Uses static keyword to achieve late static binding.

• Languages with Early Static Binding:

  • Java: Static members are resolved at compile-time based on the defining class.
  • C#: Follows the same pattern as Java.
  • C++: Uses early static binding for static members.
  • Swift: Resolves static members at compile-time.
  • Kotlin: Uses early static binding for static members.
  • TypeScript: Follows JavaScript's early static binding behavior.

Late Static Binding in Dynamically Typed Languages

In general, late static binding is more naturally supported in dynamically typed languages where runtime behavior can be more flexible. Besides PHP, other dynamically typed languages like Python and Ruby can achieve similar dynamic behavior, but they do not have a direct equivalent of PHP's static keyword.

• Python:

  • Python doesn't have late static binding as PHP, but it allows dynamic method resolution through its class and instance methods, and the use of self and cls.

• Ruby:

  • Ruby uses class methods and instance methods to achieve flexible method resolution, but it doesn't have a direct equivalent to PHP's late static binding.

Conclusion

Late static binding is a feature primarily seen in PHP and is rare in other languages, especially statically typed ones. Most statically typed languages, like Java, C#, and C++, use early static binding where static members are resolved at compile-time based on the class where they are defined. Dynamically typed languages like Python and Ruby can achieve similar dynamic behavior but do not provide a direct equivalent to PHP's late static binding.