Java 8 LongConsumer example

In this blog post, I will be explaining how the Java 8 functional interface LongConsumer works. To know more about functional interfaces, you can refer this blog post.

The LongConsumer interface provides a method called accept. It accepts a single parameter of long data type. It does not return anything, it returns a void. So it operates via side effects i.e. it modifies the parameter passed in.The LongConsumer interface is a specialization of the Consumer interface. While the Consumer interface accepts any data type, the LongConsumer interface accepts a long value. To see an example of the Consumer interface, refer to this blog post.

LongConsumer Example

Consider the following code snippet:

public class LongConsumerDemo {

  public static void main(String args[]) {
    LongConsumer decrementBy5 = (num) -> System.out.println("Input:"+num+", Incremented Value:"+(num-5));
    decrementBy5.accept(12);
    decrementBy5.accept(23);
  }

}

Here, the LongConsumer.accept method accepts a long value. It decrements the value by 5 and prints the result.  So when the above code is executed, it will print the following output:

Input:12, Incremented Value:7
Input:23, Incremented Value:18

You can get the source code for this example along with other code for other Java 8 examples at the Github repository here.