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Activity 1.8 Math Methods and Random Numbers

Introduction

This lesson introduces you to some essential math methods and constants provided by the C# Math class. These tools will be invaluable throughout your programming journey, helping you perform advanced mathematical operations with ease. Here are some of the methods and constants we’ll cover:

Random Number Generation

Another interesting aspect of programming is the ability to generate random numbers. This capability allows us to create dynamic games involving chance, automatically generate data, and much more.

In C#, we use the Random class to generate random numbers. We create a variable with the data type Random. This variable gives us access to a method called Random.Next(). The syntax for creating this variable and using this method is a little foreign, but don’t worry—we’ll dive deeper into this syntax in later sections.

Some programming languages will generate a random range of numbers, but the top number we specify isn’t included in the range of possible numbers. This is called an exclusive upper bound. It might seem odd, but it serves a purpose. Just remember the syntax for now; we’ll discuss its practical uses later.

Random random = new Random();
int randomNumber = random.Next(1, 101); // Generates a number between 1 and 100
Console.WriteLine("Random number between 1 and 100: " + randomNumber);

Example Video

Skills to Practice

Instructions

Setup

  1. Create a new C# console application. Name the project 1.8 Math Methods and Random Numbers.
  2. Click Create.

Code

Console.WriteLine("--- Demo 1 - Circumference Calculator ---\n");

Console.Write("Enter radius: ");
double radius = Convert.ToDouble(Console.ReadLine());
double circumference = 2 * Math.PI * radius;

Console.WriteLine($"Radius: {radius}, Circumference: {circumference}");
Console.WriteLine($"Rounded circumference {Math.Round(circumference, 2)}\n");


Console.WriteLine("Press enter to continue...");
Console.ReadLine();


Console.WriteLine("--- Demo 2 - More Math Functions --");

Console.WriteLine("-Exponents-");
Console.Write("Enter base number: ");
double number = Convert.ToDouble(Console.ReadLine());
Console.Write("Enter exponent: ");
double exponent = Convert.ToDouble(Console.ReadLine());
// Caret (^) can be used to symbolize exponents in plain text
Console.WriteLine($"{number}^{exponent} is {Math.Pow(number, exponent)}\n");

Console.WriteLine("-Square Roots-");
Console.Write("Enter a positive number: ");
number = Convert.ToDouble(Console.ReadLine());
Console.WriteLine($"The square root of {number} is {Math.Sqrt(number)}\n");


Console.WriteLine("Press enter to continue...");
Console.ReadLine();


Console.WriteLine("--- Demo 3 - Random Number Generation ---");
Random random = new Random();

int n1 = random.Next(1, 11); // 1 to 10
int n2 = random.Next(1, 1001); // 1 to 1000

Console.WriteLine($"Random number between 1 and 10: {n1}");
Console.WriteLine($"Random number between 1 and 1000: {n2}");

Debug

--- Demo 1 - Circumference Calculator ---

Enter radius: 5
Radius: 5, Circumference: 31.41592653589793
Rounded circumference 31.42

Press enter to continue...

--- Demo 2 - More Math Functions --
-Exponents-
Enter base number: 3
Enter exponent: 4
3^4 is 81

-Square Roots-
Enter a positive number: 16
The square root of 16 is 4

Press enter to continue...

--- Demo 3 - Random Number Generation ---
Random number between 1 and 10: 10
Random number between 1 and 1000: 6

Tips, Tricks, and Reflection