java "->"

interface LambdaFunction {
    void call();
}
class FirstLambda {
    public static void main(String []args) {
        LambdaFunction lambdaFunction = () -> System.out.println("Hello world");
        lambdaFunction.call();
    }
}Runnable r = ()-> System.out.print("Run method");

// is equivalent to

Runnable r = new Runnable() {
            @Override
            public void run() {
                System.out.print("Run method");
            }
        };