Lambda Expressions in Java

A lambda expression, introduced in Java 8 is similar to a block of code resembling an anonymous function that can be passed to constructors or methods for execution as an argument.

Examples:

a)() -> System.out.println("Hello Lambda")
b)(int x) -> 3
   x -> { 
          System.out.println(x + 2);
          return x +3;
        }

In the first example :

() identifies the lambda's parameter list (there are no parameters),

 -> indicates that the expression is a lambda

System.out.println("....") is the code to be executed which prints the string "Hello Lambda".

In the Second Example:

(x) identifies the lambda's parameter list (x is an input parameter),

 -> indicates that the expression is a lambda

System.out.println("....") is the code to be executed which calculates the value of x + 2 and prints it. Also assigns a value of x+3 = 6 to variable x which had an initial value of 3.