With this function you can check to see if a data structure of the given type exists. You supply the "index" value (as held in a variable) and the ds "type", which can be any of the constants listed below, and the function will return true if the data structure exists and false otherwise.
|ind||The variable index to check for the data structure|
|type||The type of data structure to check for (see the list of constants below)|
if !ds_exists(ai_grid, ds_type_grid)
ai_grid = ds_grid_create(room_width / 32, room_height / 32);
The above code checks the (previously initialised) variable "ai_grid" to see if it indexes a ds_grid type data structure, and if it does not then it creates one and stores its index in the variable.