Syntax of Lambda expressions

A Lambda expression consists of two parts: 0 or more arguments and the function body:

argument -> function 
(argument1,argument2,...argument) -> function 

Let's discuss it with examples. Consider a list of integers as follows:

List<Integer> list = Arrays.asList(1,2,3,4,5);

Print each element of the list using Lambda:

list.forEach(n-> System.out.println(n));

Multiply each element of the list by 2:

list.stream().map(n -> n*2 );

Here, we do not need to specify the type of n. The type of n is auto-inferred in Lambda. Also, we have not specified any return statement. The return statement is implicit in Lambda. If you want, you can specify the return statement explicitly as follows:

list.stream().map(n -> { 
      return n*2; 
   }); 
}