Equivalent for Python's lambda functions in Java?

Question

Can someone please tell me if there is an equivalent for Python\'s lambda functions in Java?

Answer 1

Unfortunately, there are no lambdas in Java until Java 8 introduced Lambda Expressions. However, you can get almost the same effect (in a really ugly way) with anonymous classes:

interface MyLambda {
    void theFunc(); // here we define the interface for the function
}

public class Something {
    static void execute(MyLambda l) {
        l.theFunc(); // this class just wants to use the lambda for something
    }
}

public class Test {
    static void main(String[] args) {
        Something.execute(new MyLambda() { // here we create an anonymous class
            void theFunc() {               // implementing MyLambda
                System.out.println("Hello world!");
            }
        });
    }
}

Obviously these would have to be in separate files :(