How is a while loop used in Perl?

The while loop is sort of like a repeating if statement in that it has a boolean expression and repeats its set of code so long as that expression continues to be true. If the expression equals false when the while loop checks it, the loop does not execute, and the code continues.

In programming, the while loop is used to iterate a function a certain number of times. This is especially useful in code that uses a lot of variables. Since certain variables might change each time a program runs, the while loop is used to help perform the correct number of operations. The number of operations might not be constant from run to run, but the number can almost always be calculated as some ratio or relationship between variables.

If a while loop has a condition that is always true, then it loops infinitely. To avoid this, there is always some line of code in the loop that affects the condition. For example, if the loop's condition were while one thing was less than another, the last line of code in the while loop might increase the smaller item by a certain amount. This repeats until that smaller thing is the same size or greater than the other thing, which makes the loop condition false and breaks the loop.