BiFunction (Java SE 9 & JDK 9 )
Keywords: java.util.function.BiFunction interface

Module java.base
Package java.util.function

## Interface BiFunction<T,U,R>

- Type Parameters:
    `T` - the type of the first argument to the function
    `U` - the type of the second argument to the function
    `R` - the type of the result of the function
  All Known Subinterfaces:
    `BinaryOperator<T>`
  Functional Interface:
    This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

      @FunctionalInterface
      public interface BiFunction<T,U,R>

  Represents a function that accepts two arguments and produces a result. This is the two-arity specialization of `Function`.

  This is a functional interface whose functional method is `apply(Object, Object)`.

  Since:
    1.8
  See Also:
    `Function`

- - ### Method Summary

    All Methods Instance Methods Abstract Methods Default Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `default <V> BiFunction<T,U,V>` | `andThen​(Function<? super R,? extends V> after)` | Returns a composed function that first applies this function to its input, and then applies the `after` function to the result.
    `R` | `apply​(T t, U u)` | Applies this function to the given arguments.

- - ### Method Detail

    - #### apply

          R apply​(T t,
                  U u)

      Applies this function to the given arguments.
      Parameters:
        `t` - the first function argument
        `u` - the second function argument
      Returns:
        the function result

    - #### andThen

          default <V> BiFunction<T,U,V> andThen​(Function<? super R,? extends V> after)

      Returns a composed function that first applies this function to its input, and then applies the `after` function to the result. If evaluation of either function throws an exception, it is relayed to the caller of the composed function.
      Type Parameters:
        `V` - the type of output of the `after` function, and of the composed function
      Parameters:
        `after` - the function to apply after this function is applied
      Returns:
        a composed function that first applies this function and then applies the `after` function
      Throws:
        `NullPointerException` - if after is null