For Loop in C#

For loop is a control flow statement used to iterate a specific number of times, We can change loop behavior at any time.

Syntax

for (initialization; condition; iteration)
{
    // Code to be executed during each iteration
}

Example 1

for (int i = 1; i < 6; i++)
{
    Console.WriteLine("External Loop " + i);
}

This loop will run five times. Here's what happens during each iteration.

Iteration 1: 
    - i is initialized to 1.
    - The condition i < 6 is true because 1 is less than 6.
    - It prints "External Loop 1".

Iteration 2: 
    - i is incremented to 2.
    - The condition i < 6 is true because 2 is less than 6.
    - It prints "External Loop 2".

Iteration 3: 
    - i is incremented to 3.
    - The condition i < 6 is true because 3 is less than 6.
    - It prints "External Loop 3".

Iteration 4: 
    - i is incremented to 4.
    - The condition i < 6 is true because 4 is less than 6.
    - It prints "External Loop 4".

Iteration 5: 
    - i is incremented to 5.
    - The condition i < 6 is true because 5 is less than 6.
    - It prints "External Loop 5".

After this, i is incremented to 6. Since 6 is not less than 6, the loop terminates, and the program moves to the next statement after the loop.

Result

External Loop 1
External Loop 2
External Loop 3
External Loop 4
External Loop 5

Example 2

Nested loop structure in C#, One loop inside of another loop.

for (int i = 1; i < 6; i++) // Outer Loop
{
    Console.WriteLine("External Loop " + i);

    for (int j = 0; j <= 5; j++) // Inner Loop
    {
        Console.WriteLine("Internal Loop " + j);
    }
}

• Outer Loop: This loop iterates from 1 to 5 (i starts at 1 and ends when it's less than 6).
• Inner Loop: Inside each iteration of the outer loop, there's an inner loop that iterates from 0 to 5 (j starts at 0 and ends when it's less than or equal to 5).

Here's how the execution flows.

Iteration 1 of Outer Loop (i = 1):
    Prints "External Loop 1".
    Enters the Inner Loop:
        Iterates from 0 to 5 and prints "Internal Loop 0" through "Internal Loop 5".
Iteration 2 of Outer Loop (i = 2):
    Prints "External Loop 2".
    Enters the Inner Loop again.
        Iterates from 0 to 5 and prints "Internal Loop 0" through "Internal Loop 5".
This process continues until the outer loop finishes its iterations.

Overall, this nested loop structure will output a sequence of messages indicating both the current iteration of the outer loop and the iteration of the inner loop within each iteration of the outer loop.

Result

External Loop 1
Internal Loop 0
Internal Loop 1
Internal Loop 2
Internal Loop 3
Internal Loop 4
Internal Loop 5
External Loop 2
Internal Loop 0
Internal Loop 1
Internal Loop 2
Internal Loop 3
Internal Loop 4
Internal Loop 5
External Loop 3
Internal Loop 0
Internal Loop 1
Internal Loop 2
Internal Loop 3
Internal Loop 4
Internal Loop 5
External Loop 4
Internal Loop 0
Internal Loop 1
Internal Loop 2
Internal Loop 3
Internal Loop 4
Internal Loop 5
External Loop 5
Internal Loop 0
Internal Loop 1
Internal Loop 2
Internal Loop 3
Internal Loop 4
Internal Loop 5