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C# Loops

Repeat an action with a for loop.

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The concept

The initializer runs once. The condition is checked before each iteration. The increment runs after each body execution.

using System;
class Program {
  static void Main() {
    for (int i = 1; i <= 3; i++) {
      Console.WriteLine(i);
    }
  }
}

Output

1
2
3

Open the walkthrough to inspect the example one step at a time.

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1using System;

2class Program {

3 static void Main() {

4 for (int i = 1; i <= 3; i++) {

5 Console.WriteLine(i);

6 }

7 }

8}

Start to inspect the source, values, and output. These prepared steps explain the published sample; grouped loop steps describe multiple iterations.

View the complete dry-run table

Prepared trace of the published program. Some rows group repeated iterations.
Step / line	What happens	State after step	Output so far
	Start i at 1; run while i is no greater than 3.	`—`	—
	Print i, increment it, and repeat for 2 and 3.	`i = 1 → 2 → 3 → 4`	1 2 3

How C# processes this code

C# compiles to code for the .NET runtime, which invokes the program entry point.