Learn the syntax, data types, and operations essential for programming in Scala

Become a Scala Developer

In this module, we will learn Scala from the ground up. This module aims to teach us how to write basic programs, assuming we have no prior knowledge of the language. We will start with a brief introduction to Scala to understand its functionality and applications. We will then move discuss the key features and functions of the language (data types, functions, classes, etc.) in detail. In the end, we will have all the basic knowledge of how to program in Scala.

Learn Scala from Scratch

## Task

In this challenge, you had to create a non-recursive factorial function `fact` in terms of a curried function `product` which calculates the product of the values of a function for the points on a given interval.


## Solution

A skeleton of the function was already provided for you. Let's look it over.

```scala
def product(f: Int => Int)(a: Int, b: Int): Int ={
  if(a > b) 1
  else f(a) * product(f)(a+1,b)
}

def fact(n: Int) = {
  
}
```

`product` is a recursive curried function and has 2 parameter lists. 
1. The first parameter list contains a single parameter; a function which has a single parameter of type `Int` and returns an integer.
2. The second parameter list contains two parameters `a` and `b`, both of type `Int`. `a` represented the minimum bound of the interval and `b` represented the maximum bound.

`fact` has a single parameter `n` of type `Int`. `n` is the integer in question whose factorial is to be computed.

To write the function body of `fact`, you needed to call `product` and pass it an anonymous function that acts as an identifier and returns the integer as is.  

```scala
x => x
```

The second argument to be passed to `product` was the interval `a-b`.
Since a factorial of a number `n` is simply the product of **1** and all consecutive numbers until `n`, our range was simply:

```scala
(1, n)
```

You can find the complete solution below:

>You were required to write the code on **line 7**.

# Task

In this challenge, you had to create a non-recursive factorial function `fact` in terms of a curried function `product` which calculates the product of the values of a function for the points on a given interval.


# Solution

A skeleton of the function was already provided for you. Let's look it over.

```scala
def product(f: Int => Int)(a: Int, b: Int): Int ={
  if(a > b) 1
  else f(a) * product(f)(a+1,b)
}

def fact(n: Int) = {
  
}
```

`product` is a recursive curried function and has 2 parameter lists. 
1. The first parameter list contains a single parameter; a function which has a single parameter of type `Int` and returns an integer.
2. The second parameter list contains two parameters `a` and `b`, both of type `Int`. `a` represented the minimum bound of the interval and `b` represented the maximum bound.

`fact` has a single parameter `n` of type `Int`. `n` is the integer in question whose factorial is to be computed.

To write the function body of `fact`, you needed to call `product` and pass it an anonymous function that acts as an identifier and returns the integer as is.  

```scala
x => x
```

The second argument to be passed to `product` was the interval `a-b`.
Since a factorial of a number `n` is simply the product of **1** and all consecutive numbers until `n`, our range was simply:

```scala
(1, n)
```

You can find the complete solution below:

>You were required to write the code on **line 7**.

In the following lesson, we will go over the solution of the challenge:  Using a Curried Function. 

Getting to Know Scala

Variables and Types

Operating with Operators

Strings and How to Use Them

Scala's Collection Library

Control Structures

Getting Started with Functions

Higher-Order Functions

Classes and Objects

Conclusion

Solution Review: Using a Curried Function

Task

Solution