#Java8 #Notes

Java8Note.md

Lambda Expressions

• Lambda expressions are anonymous method(methods without names) that implement abstract function of functional interfaces.
• An interface with single abstract method is called functional interface. Example: Runnable interface with run() method.
• Arraow Operator
  • Arrow operator divides lambda expression into 2 parts
  • (n) -> n*n;
  • The left side specifies the parameters required by the expression, which could also be empty if no parameters are required.
  • The right side is the lambda body which specifies the actions of the lambda expression. It might be helpful to think about this operator as “becomes”. For example, “n becomes n*n”, or “n becomes n squared”.

        interface NumericTest {
        boolean computeTest(int n); 
      }
  
      public static void main(String args[]) {
        NumericTest isEven = (n) -> (n % 2) == 0;
        NumericTest isNegative = (n) -> (n < 0);
  
        // Output: false
        System.out.println(isEven.computeTest(5));
  
        // Output: true
        System.out.println(isNegative.computeTest(-5));
      }