Loops

When you need to run a piece of code multiple times in a row, you use a loop.

While Loop

Repeats as long as the condition is true.

int i = 1;

while (i <= 5)
{
    Console.WriteLine(i);
    i++; // increases by 1 each time
}

Do…While Loop

Runs at least once — even if the condition is false.

int i = 1;

do
{
    Console.WriteLine(i);
    i++;
}
while (i <= 5);

The difference from while is that it runs the code first, and then checks the condition afterward.

For Loop

Used when you know exactly how many times the code should run.

for (int i = 0; i < 5; i++)
{
    Console.WriteLine("Hello!");
}

Foreach Loop

Used to go through (read) all the elements in an array or a list.

string[] names = {"Ali", "Sara", "Reza"};

foreach (string name in names)
{
    Console.WriteLine(name);
}

Control Statements Inside Loops

Break

Used to exit a loop immediately at any point.

for (int i = 1; i <= 10; i++)
{
    if (i == 5)
        break;

    Console.WriteLine(i);
}

// Output:
1  
2  
3  
4

Continue

Used to skip the current iteration and move to the next one.

for (int i = 1; i <= 5; i++)
{
    if (i == 3)
        continue; // skip number 3

    Console.WriteLine(i);
}

// Output:
1  
2  
4  
5