C++ While Loop

C++ Loops

Loops can execute a block of code as long as a specified condition is reached.

Loops are handy because they save time, reduce errors, and they make code more readable.

C++ While Loop

The while loop loops through a block of code as long as a specified condition is true:

Syntax

while (condition) {
  // code block to be executed
}

In the example below, the code in the loop will run, over and over again, as long as a variable (i) is less than 5:

Example

int i = 0;
while (i < 5) {
  cout << i << "\n";
  i++;
}

Note: Do not forget to increase the variable used in the condition (i++), otherwise the loop will never end! Do you wonder why we use the letter i as a variable name? It's a counter variable and a common choice in simple loops because it's short, traditional, and stands for 'index' or 'iterator'.

Countdown Example

This example counts down from 3 to 1 and then displays "Happy New Year!!" at the end:

Example

int countdown = 3;

while (countdown > 0) {
  cout << countdown
<< "\n";
  countdown--;
}

cout << "Happy New Year!!\n";