This section of the manual contains all the information required
to understand and use the GameMaker Studio 2 scripting
language GML. The code in this language can be used to
create your games and is added into objects from the Object Editor,
normally when you've chosen to make a new GameMaker
Language Project, although it can also be used along with
DnD™ (Drag and
Drop). Below you can see a typical image of an object with the code
editor open on an event: 
Each
event has its own tab in the editor and you can add, edit, or
remove code from them at any time (for more information on events
see Object
Events). The code itself must have a basic structure and can
contain resource indices, variables, functions, expressions,
keywords... etc... all of which are explained in the sections
below. If you are a novice to programming or making the switch from
DnD™, it is recommended that you start with the page on Basic Code Structure and then read through them
all, testing code from each of the sections within GameMaker
Studio 2 itself.