Method references


Method references give idiomatic feel to the function reference there by making the code more readable. 

If the lambda expression is only having a call to other instance method, then, the lambda syntax can be replaced by that method reference.
 It is just a syntactic change, nothing more than that.

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private void test(Consumer<? super Integer> consumer){
  //.....
 }


 public void instantiateConsumer(){
               //Before Lambda's  - Prior to Java 8
  test(new Consumer<Integer>() {
   @Override
   public void accept(Integer val) {
    System.out.println(val);
   }
  });
  
               //Using Lambda
  test(val -> System.out.println(val));
  
               //Method reference
  test(System.out::println);
      }


Using the method reference, above code is simplified verbosely using Lambda first and method reference later.

Prior to Java 8, we had to create a class for consuming a method since method was not a first class citizen in java which means method was not treated the same way as object. methods cant be passed as arguments. you need to wrap them inside a class.


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