LongToDoubleFunction 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 accepts a long-valued argument and produces a double-valued result. As it is a functional interface, it can be used assignment target for lambda expression or method reference. In this post, we are going to see several implementations of LongToDoubleFunction Interface by using different examples.

LongToDoubleFunction Interface in Java 8 with Examples...!!! Share on X
Look at LongToDoubleFunction Javadoc description below:

LongToDoubleFunction Interface contains following method:
applyAsDouble
This method performs operation on the given long-valued argument and return an double-valued result.
double applyAsDouble(long value);
Lets understand above mentioned method through below example:
Example: ‘applyAsDouble’ method
import java.util.function.LongToDoubleFunction;
public class LongToDoubleFunctionInterfaceJava8Example {
public static void main(String[] args) {
System.out.println("LongToDoubleFunction Interface - 'applyAsDouble' example \n");
LongToDoubleFunction longToDoubleFuncObj = i -> i * 2;
System.out.println("Result: " + longToDoubleFuncObj.applyAsDouble(5l));
}
}
Output:
LongToDoubleFunction Interface - 'applyAsDouble' example Result: 10.0
Java 8 LongToDoubleFunction Interface is an absolute useful addition as part of ‘Functional Interfaces’ and can serve variety of purposes. It is quite powerful as it can be used as a higher order functions through lambda functions and above examples could help you to get better idea on how to implement it.
LongToDoubleFunction Interface in Java 8 with Examples...!!! Share on X
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