ToLongFunction 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 expect an argument as an input and produces a long-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 ToLongFunction Interface by using different examples.
ToLongFunction Interface in Java 8 with Examples...!!! Share on X
Look at ToLongFunction Javadoc description below:
ToLongFunction Interface contains below method:
applyAsLong
Let’s discuss this method:
applyAsLong
This method performs operation on the given argument and return the Long-valued result.
long applyAsLong(T value);
Let’s understand above mentioned method through below example:
Example. ‘applyAsLong’ method
import java.util.function.ToLongFunction;
public class ToLongFunctionInterfaceJava8Example {
public static void main(String[] args) {
System.out.println("ToLongFunction Interface - 'applyAsLong' example \n");
//1. anonymous implementation
ToLongFunction <String> anonymousObj = new ToLongFunction <String> () {
@Override
public long applyAsLong(String t) {
return Long.parseLong(t) * 5;
}
};
//2. lambda implementation
ToLongFunction <String> lambdaObj = t -> Long.parseLong(t) * 5;
//1
System.out.println("Result of 5 times of number 5: " + anonymousObj.applyAsLong("5"));
//2
System.out.println("Result of 5 times of number 5: " + lambdaObj.applyAsLong("5"));
}
}
Output:
ToLongFunction Interface - 'applyAsLong' example Result of 5 times of number 5: 25 Result of 5 times of number 5: 25
Java 8 ToLongFunction 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.
ToLongFunction Interface in Java 8 with Examples...!!! Share on X
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