LongUnaryOperator Interface is a part of the java.util.function package which is introduced in Java 8. It is an in-built Functional Interface. This function expects an argument of type long as input but produces the output of same type as input argument. In this post, we are going to see several implementations of LongUnaryOperator Interface by using different examples.
LongUnaryOperator Interface in Java 8 with Examples...!!! Click To Tweet
Look at LongUnaryOperator Javadoc description below:
LongUnaryOperator Interface contains 4 methods:
applyAsLong
compose
andThen
identity
Let’s discuss these methods:
identity
This method returns a long unary operator that always returns its input argument.
1 2 3 | static LongUnaryOperator identity() { return t -> t; } |
applyAsLong
This method performs operation on the given argument and return the function result.
1 | long applyAsLong(long operand); |
Compose
This method returns a composed operator that first applies the before operator to its input, and then applies this operator to the result. If evaluation of either operator throws an exception, it is relayed to the caller of the composed operator.
1 2 3 4 | default LongUnaryOperator compose(LongUnaryOperator before) { Objects.requireNonNull(before); return (long v) -> applyAsLong(before.applyAsLong(v)); } |
andThen
This method returns a composed operator that first applies this operator to its input, and then applies the after operator to the result. If evaluation of either operator throws an exception, it is relayed to the caller of the composed operator.
1 2 3 4 | default LongUnaryOperator andThen(LongUnaryOperator after) { Objects.requireNonNull(after); return (long t) -> after.applyAsLong(applyAsLong(t)); } |
Below are the several examples to demonstrate above methods:
Example 1. ‘applyAsLong’
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | import java.util.function.LongUnaryOperator; public class LongUnaryOperatorInterfaceJava8Example1 { public static void main(String[] args) { System.out.println("LongUnaryOperator Interface - 'applyAsLong' example \n"); LongUnaryOperator obj1 = d -> d * 5; System.out.println("Value of Obj 1: " + obj1.applyAsLong(10)); } } |
Output:
1 2 3 | LongUnaryOperator Interface - 'applyAsLong' example Value of Obj 1: 50 |
Example 2. ‘andThen’
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | import java.util.function.LongUnaryOperator; public class LongUnaryOperatorInterfaceJava8Example2 { public static void main(String[] args) { System.out.println("LongUnaryOperator Interface - 'andThen' example \n"); LongUnaryOperator obj1 = d -> d * 5; LongUnaryOperator obj2 = d -> d + 5; System.out.println("Result: " + obj1.andThen(obj2).applyAsLong(10)); } } |
Output:
1 2 3 | LongUnaryOperator Interface - 'andThen' example Result: 55 |
Example 3. ‘compose’
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | import java.util.function.LongUnaryOperator; public class LongUnaryOperatorInterfaceJava8Example3 { public static void main(String[] args) { System.out.println("LongUnaryOperator Interface - 'compose' example \n"); LongUnaryOperator obj1 = d -> d * 5; LongUnaryOperator obj2 = d -> d + 5; System.out.println("Result: " + obj1.compose(obj2).applyAsLong(10)); } } |
Output:
1 2 3 | LongUnaryOperator Interface - 'compose' example Result: 75 |
LongUnaryOperator Interface in Java 8 with Examples...!!! Click To Tweet
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