A while loop looks a bit like an if statement:

while (silliness > 10) {

  // code to run

}

Like an if statement, the code inside a while loop will only run if the condition is true. However, a while loop will continue running the code over and over until the condition evaluates to false. So the code block will repeat until silliness is less than or equal to 10.

// set attempts to 0
int attempts = 0;

// enter loop if condition is true
while (passcode != 0524 && attempts < 4) {

  System.out.println("Try again.");
  passcode = getNewPasscode();
  attempts += 1;

  // is condition still true?
  // if so, repeat code block
}
// exit when condition is not true

while loops are extremely useful when you want to run some code until a specific change happens. However, if you aren’t certain that change will occur, beware the infinite loop!

Infinite loops occur when the condition will never evaluate to false. This can cause your entire program to crash.

int hedgehogs = 5;

// This will cause an infinite loop:
while (hedgehogs < 6) {

  System.out.println("Not enough hedgehogs!");

}

In the example above, hedgehogs remains equal to 5, which is less than 6. So we would get an infinite loop.