The lambda expression example does not work in Java 8

I'm trying to learn lambda expression in Java 8 I did install the Eclipse Plug-in and Java 8 SDK, but when I tried to execute the following code, eclipse showed an error

(String s) -> { 
            s="hello";
            System.out.println(s); }

It displays the error "the left side of the assignment must be a variable"

Please help.

Solution

Lambda expressions (and method references) are meaningful only in the context of an instance that requires a functional interface Otherwise, it will be impossible to determine whether the lambda is valid (and because you haven't done anything about it, it's useless)

It's like

Consumer<String> c = (String s) -> {
    s = "hello";
    System.out.println(s);
}; // as a Consumer,it doesn't really make sense for you to change s