Reshma Bidikar

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

What is IntBinaryOperator

IntBinaryOperator is an in-built functional interface in the java.util.Function package. It accepts two int arguments, operates on it and produces a result of type int. It is a specialization of the BinaryOperator interface. It has a applyAsInt method. It applies the logic in this method on the int arguments passed in and produces an int result.

IntBinaryOperator Code Sample

The following code demonstrates this interface:

IntBinaryOperator intBinaryOp = (num1,num2) -> num1+num2;
int input1=14,input2=12;
int result = intBinaryOp.applyAsInt(input1, input2);
System.out.println("result:"+result);

• Line 1 declares a IntBinaryOperator instance intBinaryOp and implements it via a lambda expression that adds the input arguments and returns the result.
• Line 3 invokes the applyAsInt method on some input values.

This code prints the following output:

result:26

Why IntBinaryOperator

The IntBinaryOperator interface is a non-generic primitive specialization of the BinaryOperator interface. The other functional interfaces like Supplier, Predicate,Consumer also have primitive specializations like IntSupplier, LongPredicate, IntConsumer, etc. The primitive specializations help to improve performance when the input parameters are of primitive types. For example, in the above example, we can also use a BinaryOperator interface as follows:

BinaryOperator<Integer> binaryOp = (num1,num2) -> num1+num2;
int input1=14,input2=12;
int result = binaryOp.apply(input1, input2);
System.out.println("result:"+result);

• Line 1 declares a BinaryOperator instance binaryOp and implements it via the same lambda expression as used above.
• Line 3 then invokes the apply method on the values 14, 12. Since the input value is a primitive type, Java uses autoboxing to convert the primitive int type to the wrapper type that is Integer before applying the lambda expression. This reduces the performance slightly. However, in the case of IntBinaryOperator, no such conversion is required since the applyAsInt method accept arguments of type int already. Thus the primitive specialization offers a slight performance advantage as it does away with the need of autoboxing.

Conclusion

So in this article, we took a look at the IntBinaryOperator interface. This interface is a specialization of the BinaryOperator interface that accepts int parameters and returns an int result.