Java中的JavaScript匿名函数

Question

I am new to JavaScript and have some intermediate knowledge of Java, after a few exercise, I am left with a puzzling question is there a way to apply the concept of anonymous functions in Java? is it even possible? I am well aware of the criticism I might receive for asking this question but I am asking anyway. An example of JavaScript anonymous function is below.

var myResult = (function () {
            return arguments[0] + arguments[1];
    }) (1,2);
alert(myResult);

Answer 1

Using @FunctionalInterface Java 8

public class Test {
    @FunctionalInterface
        public interface Func {
        public String concat(String a, String b);
    }

    public static void main(String[] args) {
        Func func = (a, b) -> a + b;
        System.out.print(func.concat("Hello ", "World!"));
    }
}

Answer 2

Anonymous inner classes do exactly that. A function cannot exist on its own in Java; it has to be wrapped in a class. So, the closest thing to an anonymous function is an anonymous inner class.

int myResult = (new Object() {
public int calc(int[] args){
        return args[0] + args[1];
    } }).calc( new int[]{ 1, 2} );
System.out.println(myResult);

This can now be easily done using Java 8 using lambda expressions (with functional interfaces).