I don't really understand this topic pls help me out with exampl

Answer 1

If you can add Language name in tags it would be easy for someone to provide an example in that particular syntax

Answer 2

Pseudo code, generic with no valid syntax for specific language:

Loop for given lists, ranges:
for entry in list {
doSthWith(entry)
}

Loop for not pre-defined length:
while sthIsTrue do {
doSth(with anything)
}

Last case may be changed to be first executed and checked (while-condition fulfilled or not) afterwards.