what is method reference in java code example

Example 1: java method

public class Main {
  public static void main(String args[]) {
    SayHi();
    
    int sum = AddNums(5, 6);
    System.out.println(sum);
  }
  
  public static void SayHi() { //This method has no return value
    System.out.println("Hi!");
  }
  
  public static int AddNums(int a, int b) { //This method has a return value
    return a + b;
}

Example 2: java method reference

Java provides a feature called method
reference in Java 8. Method reference 
is used to refer method of functional interface.
  It is compact and easy form
  of lambda expression. Each time when 
  you are using lambda expression to just
  referring a method, you can replace your
  lambda expression with method reference.

Types of Method References:
- Reference to a static method.  Syntax ==> ContainingClass::staticMethodName  
- Reference to an instance method.  Syntax ==> containingObject::instanceMethodName  
- Reference to a constructor.  Syntax ==> ClassName::new

Example 3: method in java

Method is a collection of statements
which returns a value upon its execution
Method have a return and the method's name may or not be same as the class
name.
Method is invoked explicitly.
Method is not provided by compiler in any case.
Methods are inherited by child classes.

Example 4: what are method in java

Static methods: A static method is a method that can be called and executed without creating an object
Instance methods: These methods act upon the instance variables of a class
Factory methods: A factory method is a method that returns an object to the class to which it belong