_{Official ZPE/YASS documentation}While loops

A while loop will loop while a condition is true.

while($a < 10)
  //Do something
end while
  

A common form of while loop is the while-true loop. This loop will continue indefinitely since there is no condition from which it will stop. It can be broken by a return or break command, however.

while(true)
  //Do something
end while
        

As with all loops, while loops may be terminated by end loop.

while($a < 10)
  //Do something
end loop
  

Do while loops

Version 1.5.1 added do while loops. These loops are incredibly simple to use and work exactly as a standard while loop does except with one subtle difference. A while loop may not necessarily execute a statement:

$a = 0
while($a > 10)
  //Do something
end loop
  

With a do while loop it is guaranteed to execute at least once. Many other languages out there also implement a do while loop that works similarly. Below is an example of a do while loop in YASS:

$a = 0
do
  //Do something
loop while($a > 10)
  

Loop until

Another form of loop, similar in syntax to the while loop, is loop until. This loop will loop while a condition is false or until a condition is true.

$a = 0
loop until($a > 10)
  //Do something
end loop
  

One of the first programs I ever wrote was in Visual Basic 6 and was a guess the number game. It took several lines of code to write. With ZPE this can be done very easily.

$n = random_number(1, 20)
while(value(input("Please insert a number between 1 and 20.")) != $n)
  print("Sorry, wrong answer. Guess again.")
end while
print("Correct. The number I was thinking of was " & $n & ".")