Part-15-Functions.md

Part 15: Functions

Table of Contents
15-1: Simple Print Function
15-2: Return Function
15-3: Prime Number Function
15-4: Collections in Functions

Simple Print Function

In this function, we'll print "BADGER!". We use "def" to create the function and we need to provide the data type for the output. In this case, we'll use "Unit", which is a general data type. See the example below.

input

def badger_print():  Unit = {
    println("BADGER!")
}

badger_print()

output

Loading scala_functions.scala...
badger_print: ()Unit
BADGER!

Return Function

Let's do a quick return function. We'll create a function that takes in 2 arguments: "animal" and "name". Both will be strings. We'll then return a greeting.

input

// greeting function

def hello(animal: String, name: String): String = {
    return "Hello " + animal + " " + name + "!"
}

hello("Aardvark", "Sam")

output

hello: (animal: String, name: String)String
res0: String = Hello Aardvark Sam!

Prime Number Function

Let's create a function that tells us whether a number is prime or not. We'll then create some print statements to test it out.

input

def isPrime(num:Int): Boolean = {
    for(n <- Range(2,num)){
        if(num%n == 0){
            return false
        }
    }
    return true
}

println("10 is a prime number: " + isPrime(10)) 
println("23 is a prime number: " + isPrime(23)) 
println("2 is a prime number: " + isPrime(2))

output

isPrime: (num: Int)Boolean
10 is a prime number: false
23 is a prime number: true
2 is a prime number: true

Collections in Functions

Finally, we'll do an example of a collection in a function. We'll use our "animals" list from previous sections and create a function called "showAnimals" that will return out list of animals.

input

// using collections in functions

var animals = List("aardvark", "hedgehog", "walrus")

def showAnimals(beasts: List[String]): List[String] = {
    return beasts
}

println(showAnimals(animals))

output

animals: List[String] = List(aardvark, hedgehog, walrus)
check: (beasts: List[String])List[String]
List(aardvark, hedgehog, walrus)

Project Table of Contents

Part 1: Installation, Set-Up, and "Hello World"
Part 2: Data Types
Part 3: Arithmetic Operators
Part 4: Variables vs Values
Part 5: String Operations
Part 6: Tuples
Part 7: Lists
Part 8: Arrays
Part 9: Sets
Part 10: Maps
Part 11: Logical Operators
Part 12: If Statements
Part 13: For Loops
Part 14: While Loops
Part 15: Functions