Scala Function for Function

Scala is a functional programming language that supports higher-order functions, which means that functions can take other functions as arguments or return functions as results.

In this article, we will explore the concept of Scala function for function and how it can be used in writing concise and expressive code.

Syntax

The syntax for a function that takes a function as an argument and returns a function as a result is as follows:

def functionForFunction(fn: (Int) => String): (String) => Int = {
     (str: String) => fn(str.toInt)
}

This code defines a function functionForFunction that takes a function fn that maps an integer to a string, and returns another function that maps a string to an integer.

Example

Let's look at an example that illustrates the use of Scala function for function.

def increment(fn: (Int) => Int): (Int) => Int = {
    (x: Int) => fn(x) + 1
}

val addOne = increment((x: Int) => x)
val addTwo = increment((x: Int) => x + 1)
val addThree = increment((x: Int) => x + 2)

println(addOne(1)) // Output: 2
println(addTwo(1)) // Output: 3
println(addThree(1)) // Output: 4

In this example, we define a function increment that takes a function fn and returns another function that applies fn to its argument and adds 1 to the result. We then use increment to define three functions addOne, addTwo, and addThree, each of which increments its argument by a different amount. Finally, we apply the three functions to the argument 1 and print the results.

Conclusion

In conclusion, Scala function for function is a powerful feature that allows us to write more expressive and reusable code. By defining functions that take and return other functions, we can create higher-level abstractions that capture common patterns of computation. If you are new to Scala, we encourage you to explore this feature further and experiment with different ways of using it in your code.