1. What is this?
A loop repeats a block: for (int i = 1; i <= 5; i++) runs with i = 1..5. A method is a reusable block: static int DoubleIt(int n) takes an int and returns an int. PascalCase (DoubleIt) is the C# convention for methods.
2. Why do we use it?
One tested method, called everywhere: pricing, validation, formatting.
3. Syntax breakdown
static int DoubleIt(int n) { return n * 2; }Method declaration: returns int, takes int n.
for (int i = 1; i <= 3; i++) {Loop counter from 1 while <= 3.
System.Console.WriteLine(DoubleIt(i));
Calls the method each pass.
5. Common mistakes
- Forgetting return in a non-void method.
- Calling a non-static method from static Main.
- Off-by-one bounds.
Practice task
Make TripleIt (n * 3) and print it for i = 1..5.
Hint
Rename and change * 2 to * 3; loop to i <= 5.
Try it below — tests run automatically when you press Run.
csharp
Output
Press Run to see output.
Mini quiz
3 questions. Answer, then check.
1. What is a method?
2. C# method naming convention?
3. How many passes for i=1; i<=5?