title=Fundamentals of Programming: Randon number generation

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PAPER 1 - ⇑ Fundamentals of programming ⇑

← Built-in functions Random number generation Subroutines (functions and procedures) →


An essential part of most games is the ability to use random numbers. These might be used to randomly place gold coins on a map, or to calculate whether you hit a target with a rifle at some distance.

Dim rndGen As New Random()
Dim randomNumber As Integer
randomNumber = rndGen.Next()

The above code will give you a random number between 1 and 2,147,483,647. You might well require a number that is a little smaller. To get a random number between two set numbers, in this case 5 and 10 you can use the following:

randomNumber = rndGen.Next(5,10)

So how exactly can we use this? Take a look at the following game:

Dim rndGen As New Random()
Dim randomNumber As Integer
Dim guess as Integer
randomNumber = rndGen.Next(1,100)
console.writeline("Please guess the random number between 1 and 100")
Do 
  console.write("your guess:")
  guess = console.readline()
  if guess > randomNumber
    console.writeline("Too High")
  end if
  if guess < randomNumber
    console.writeline("Too Low")
  end if
Loop While guess <> randomNumber
console.writeline("Well done, you took x guesses to find it!")

Adjust the code above to tell the user how many guesses they took to find the random number. HINT: you'll need a variable

Answer:

    Sub Main()
        Dim rndGen As New Random()
        Dim randomNumber As Integer
        Dim guess As Integer
        Dim count As Integer = 1
        randomNumber = rndGen.Next(1, 100)


        Console.WriteLine("Please guess the random number between 1 and 100")
        Do
            Console.Write("your guess:")
            guess = Console.ReadLine()
            If guess > randomNumber Then
                Console.WriteLine("Too High")
            End If
            If guess < randomNumber Then
                Console.WriteLine("Too Low")
            End If
            If guess <> randomNumber Then
                count = count + 1
            End If
            If guess = randomNumber Then
                Console.WriteLine("Well done, you took " & count & " guesses to find it!")
            End If

        Loop
    End Sub