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# C# Dash: Level 2 - Math on track

### Sorry, saving conditionals for third tutorial.

So how did you do on the coding challenge on the last tutorial? Well I linked an example repl at the bottom of the second tutorial for some sample code for the last coding challenge.

Anyways, looks like another day of C# Dash. And we are about to start level 2, Math on Track.

# This tutorial will cover essential Math methods and variable type conversion.

## The user is expected to have read C# Dash: Level 1 - Object Oriented Madness (below), know what object oriented programming is, and know what square roots and other math around that level is.

### DISCLAIMER: These tutorials will not cover complicated concepts, but will cover a basic selection of things to make some decent code.

Words like this will appear in the glossary at the bottom.

# SO LET'S GET STARTED!!!!!!!!!

## Essential `Math` Methods

So, if you want to have more complex math in your C# program, you will have to use a `Math` method. I have a link to the .NET Online C# Documentation for math methods in my last tutorial.

I can't explain every math method in this tutorial, but here are a few essential ones:

• `Math.Sqrt()` - Returns the square root of inputted number.
• `Math.Cbrt()` - Returns the cube root of inputted number.
• `Math.Max()` - Returns the larger of two inputted numbers.
• `Math.Min()` - Returns the smaller of two inputted numbers.
• `Math.Abs()` - Returns the absolute value of inputted number.
• `Math.Pow()` - Returns the number raised to whatever you input.
• The first number is the one you want to raise.
• The second number is the power you are raising the first number by.
• `Math.Floor()` - Rounds a number down to the nearest integer.
• `Math.Ceiling()` - Rounds a number up to the nearest integer.

Example of a `Math` method:

``````using System;

class insert_class_name_here {
public static void Main (string[] args) {
double var1 = -3;
double var2 = Math.Abs(var1);
Console.WriteLine(var2);//Will output: 3
}
}``````

## Variable Conversion

Sometimes, you need to convert between types (like `string` to `double`) in order for the program to work. You write these methods for variables. This will show one method for that.

The method is `Convert`. You can convert it to different things. These are the examples for the types I showed you.

• `Convert.ToString()` - Converts a non-string variable to a string.
• `Convert.ToChar` - Converts a non-single-character variable to a single character (throws an exception if thing being converted has more than one character or is a double.)
• `Convert.ToInt32()` - Converts a non-32-bit-integer variable to a 32-bit integer and removes numbers after the floating-point.
• `Convert.ToDouble()` - Converts a non-double variable to a double.

NOTE: Converting to an int or a double with letters will throw an exception.

Example of this kind of conversion:

``````using System;

class insert_class_name_here {
public static void Main (string[] args) {
string var1 = "5.2";
double var2 = Convert.ToDouble(var1);
Console.WriteLine(var2 - 4);//Will output: 1.2
}
}``````

That was one way to convert between types.

# Level Complete!

Next tutorial will be about conditionals and arrays.

# Coding challenge (optional)

Write a program that will take a number the user typed in and write the square root for that number. There will be variable conversion and `Math` methods involved.

# Glossary

• Method - Some code that is called with `()`s. Examples include `Console.WriteLine()` and `Math.Max()`. Inside some methods, you put in arguments for output.
• Variable - Stored data under a name.
• Exception - An error occurring while program is running.