How to implement ToDoubleBiFunction<T, U> using lambda expression in Java?

ToDoubleBiFunction<T, U> is a functional interface defined in java.util.function package. This functional interface accepts two parameters as input and produces a double-valued result. ToDoubleBiFunction<T, U> interface can be used as an assignment target for a lambda expression or method reference. This interface contains only one abstract method: applyAsDouble() and doesn't contain any default or static methods.

Syntax

@FunctionalInterface
interface ToDoubleBiFunction<T, U> {
   double applyAsDouble(T t, U u);
}

Example

import java.util.function.ToDoubleBiFunction;

public class ToDoubleBiFunctionTest {
   public static void main(String args[]) {
      ToDoubleBiFunction<Integer, Integer> test = (t, u) -> t / u;   // lambda expression

      System.out.println("The division of t and u is: " + test.applyAsDouble(50, 5));
      System.out.println("The division of t and u is: " + test.applyAsDouble(100, 3));
   }
}

Output

The division of t and u is: 10.0
The division of t and u is: 33.0