Loop user input until conditions met

Question

I need to ask the user to input a number to be used as the start of a range, and then input another number that is the end of the range. The start number has to be 0 or grea

Answer 1

You need to use a while, something like:

while conditionsMet is false
    // gather input and verify
    if user input valid then
        conditionsMet = true;
end loop

should do it.