This section of the manual is a reference guide for the GameMaker Language (GML Code). You can find all the available functions documented here along with the required arguments and examples of code to show how they can be used. For information on how to use GML Code please see the GML Code Overview section of the manual.
NOTE Anywhere the manual has N/A as a return value for a function, it means that the function is not meant to return any value as part of its operation. If you try to check for a return value from these functions then you will get the value undefined.