I need help in understanding what the number (3 and 5) means in the code below.
They're so called "magic numbers", which is numbers that shows up in a piece of code without any explanation.
Magic numbers are considered very bad programming practise, as it fogs the purpose of the code.
The right way to do it, is to define them as constants in eg. the head of the code and make comments about their purpose and why they have those values etc.