While loops

A while loop is a type of condition-controlled loop that repeats a block of code as long as a certain condition is true.

In pseudocode, we might write this as:

while (condition is true) {
    // Code to repeat
}

Basic syntax

In C#, we can write a for loop like this:

while (condition) {
    // Code to repeat
}

The condition has to evaluate to a boolean value (true or false).

While loops can be confusing, but all that is happening here is that the code inside the {} is being repeated as long as the condition is true.

Example: counting to 5

Here’s an example of a while loop that counts from 1 to 5:

int count = 1;
while (count <= 5) {
    Console.WriteLine(count);
    count++; // Increment count by 1
}

Output:

1
2
3
4
5

How does this code work?

• We start by initializing a variable count to 1.
• The while loop checks if count is less than or equal to 5.
• If the condition is true:
  • it prints the value of count
  • it increments count by 1.
• This process repeats until count becomes 6, at which point the condition count <= 5 becomes false, and the loop ends.