In the module Inner Class Listeners  we discuss that lambda...

In the module Inner Class Listeners we discuss that lambda expression can be viewed as a concise representation of an anonymous method that can be passed around.

Recall that the basic syntax of a lambda is either

(parameters) -> expression

or (note the curly braces for statements)

(parameters) -> { statements; }

Following these syntax rules, which of the following are not valid lambda expressions?

• () -> {}
• () -> "Raoul"
• () -> {return "Mario";}
• (Integer i) -> return "Alan" + i;
• (String s) -> {"Iron Man";}

If an expression is not a valid lambda expression, briefly describe why.