Game Maker Language Notes

Notes that are about GameMaker Studios coding Language.

GML Game Maker Language, used by GameMaker Studio Variable A storage location in the computer memory, paired with a name, that contains data A named piece of data A box that holds something with a label on it A way to store data (to access or change it later) How to name a variable Requirements Letters(case sensitive), numbers, and underscores Star with a letter or underscore Conventions Clear and descriptive names Readability and consistency Using a Variable Set(initialize) before use ex. player_name = "Korae" player_health = 100 Changing is the same as setting ex. player_name = "Loser" player_health = player_health - 1 Reference ex. if(player_health <= 25){ draw_text(x, y, "you're low on health!") } You can't reference a variable without setting it Varialbe Scope The place where you can validly reference a variable by name Allows variables to have the same name Three Scope Categories Global Can be accessed by everything Has a special declaration ex. global.volume = 100 Remains in memory until the game ends Only use when you need to use the same information across multiple objects and only one type of that information is needed Instance Created within an instance of an object Unique to that instance Most common, no special declaration Unique to that instance Destroyed when instance is destroyed Local Created for a specific event or script Have a special declaration ex. var_value = 5 Discarded when the event has finished Good for when information needs to be created or held onto for a specific event Data Types When you create a variable it can be used to hold information, and when you call a function, it can also store returned information. However, this information can come in various "flavours" - for example, it can be a real number or it can be a string. These different types of values being used are called data types. An attribute of the data that tells the computer how to treat it Defines the operations that can be done Ex. 5*5 vs John*John Common Data Types Strings (text) Text Must use quotation marks ex. string = "Hello" Built in string functionality Real Numbers Any real number ex. number = 5 Default data type Built in number functionality Booleans (true false) A value that can be either true or false ex. bool = true Arrays (special) Data that holds other types of data Like a list The variable is not the data, but a reference to the data Built in array functionality All GML Data Types Real Numbers Boolean Strings Arrays Structs Method Variables A variable that has been assigned a function must use name = function(){} format ex. a_method = function(){//stuff} int64 Handles Hexadecimal Literals Binary Literals Pointer Enum Undefined NaN Infinity Any