How do you create functions with gamemaker language?

[CGWorks]

user-defined functions are just called Scripts in GML. Just as a simple example if you wanted to create a simple addition script that adds 2 arguments together you would:

Create a script resource and name it something like "scr_add"

open the script resource you created and then put something like:

(in GMStudio 1.x)

Code:

///scr_add(first value, second value)

return argument0 + argument1;

(in GMStudio 2.x)

Code:

///@function scr_add(first value, second value)
///@arg first value
///@arg second value

return argument0 + argument1;

Then you can call it from an object