Java 8 BinaryOperator Example

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

What is BinaryOperator

The BinaryOperator is a specialization of the BiFunction interface that accepts 2 arguments. However, unlike the BiFunction it accepts 2 arguments of the same data type and returns a result of the same data type. The BinaryOperator internally uses the BiFunction.apply method.

BinaryOperator Interface Example with Integer data type

Consider the following code snippet:

BinaryOperator<Integer> additionCalculator = (a, b) -> a +b;
int input1 = 6;
int input2 = 5;
System.out.println("Result of adding " + input1 + " and " + input2 + " is " + additionCalculator.apply(input1, input2));

Here, we have written a BinaryOperator implementation that operates on Integer data type. It accepts two integer values, adds them and returns the result. The BiFunction.apply method is implemented using a lambda expression.  So when you execute this code, it will print the following output:

Result of adding 6 and 5 is 11

BinaryOperator Interface Example with String data type

Consider the following code snippet:

BinaryOperator<String> strOperator = (str1,str2) -> str1.concat(" ").concat(str2);
String str1 = "Hello";
String str2 = "World";
System.out.println("Concatenated String:" + strOperator.apply(str1, str2));

This code demonstrates a BinaryOperator instance that operates on String values. It accepts 2 String values, concatenates them and returns the result. So when you execute this code, it prints the following output:

Concatenated String:Hello World

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

Conclusion

So in this article, we explored the Java 8 BinaryOperator interface.  We also saw a BinaryOperator example with Integer data type and String data type.