Introduction to C#

Introduction to C#: Variables, Operators, and Core Concepts

Now that you've practiced pseudocode, it's time to learn the basics of C#, the language Unity uses.

Start() vs Update()

Start() -> runs once when the scene loads; use for setup like initializing variables or references.

print("hello"); // Prints once

Update() -> runs every frame; use for input, movement, and interactions.

print("hello"); // Prints continuously

Operators: How Programs Think

Programs are sets of logical instructions. C# uses operators to express logic.

Download the spreadsheet (linked below) for full explanations and examples.

Operator types with simple explanations:

• arithmetic operators -> perform calculations;
• relational operators -> compare values, return true or false;
• logical operators -> combine conditions;
• assignment operator -> sets a value to a variable.

Arithmetic operators example:

print(2 + 3); // Adds numbers, prints 5
print(10 / 2); // Divides numbers, prints 5

Relational operators example:

print(5 > 3); // true
print(2 == 4); // false

Logical operators example:

print(true && false); // false cause only one is true
print(true || false); // true cause at least one is true

Assignment operator example:

int score = 10; // assigns 10 to score

If Statements

Code often follows: if condition is true -> do something.

if (1 > 2)
   print("yes");
else
   print("no"); // Prints "no" instead of "yes".

Every statement ends with a semicolon (;).

Variables: Storing Information

Variables store and change information like speed, position, score, text, or game states.

Declaration includes: type, name, optional starting value.

Usually declared above Start().

Common Variable Types

Download the spreadsheet (linked below, page 2) for full list with examples.

Public vs Private Variables

Private -> only accessible inside the script (default).

Public -> visible in Inspector; tweak during playtesting.

Debugging with the Console

Text must be inside quotes:

print("hello");

Forgetting quotes causes errors.

Download: Operators & Variables Spreadsheet

Happy coding!