Java 8 - Method References

Method references help to point to methods by their names. A method reference is described using :: (double colon) symbol. A method reference can be used to point the following types of methods −

• Static methods
• Instance methods
• Constructors using new operator (TreeSet::new)

Method Reference Example

Let's look into an example of method referencing to get a more clear picture. Write the following program in an code editor and match the results.

Java8Tester.java

import java.util.List;
import java.util.ArrayList;

public class Java8Tester {
   public static void main(String args[]){
      List names = new ArrayList();
  
      names.add("Mahesh");
      names.add("Suresh");
      names.add("Ramesh");
      names.add("Naresh");
      names.add("Kalpesh");
  
      names.forEach(System.out::println);
   }
}

Here we have passed System.out::println method as a static method reference.

Verify the Result

Compile the class using javac compiler as follows −

$javac Java8Tester.java

Now run the Java8Tester as follows −

$java Java8Tester

It should produce the following output −

Mahesh
Suresh
Ramesh
Naresh
Kalpesh