This is a quick tutorial following a post about transport belts I made earlier this week.
Disclaimer: I'm fairly new with working with GameMaker so I might not be following the best practices, sorry for that! Some parts of this might be refactored, but I wrote them this way for the (in my opinion) best readability for this tutorial. Also, English is not my native language.
The way we'll be implementing the transport belts is like a linked list data structure.
In computer science, a linked list is a linear collection of data elements, whose order is not given by their physical placement in memory. Instead, each element points to the next. --- Wikipedia
In other words: each belt object points to the next belt object in line.