Gamemaker studio 2 inventory how to#
Gamemaker studio 2 inventory code#

This is essentially telling GameMaker that the array is actually comprised of various 1D arrays. For example, the following is a 2D (two-dimensional) array: We now know what a 1-dimensional array is, but in GameMaker you can have arrays with multiple dimensions, which are essentially structured as an array inside an array inside an array. Multi-Dimensional Arrays Multi-Dimensional Arrays However, if any of the array positions hold references to dynamic assets, such as particle systems, buffers, or data structures, then these will need to be destroyed before the array is deleted, the instance is destroyed or the room ends. If the array has multiple dimensions (see below), they will all be cleaned up too, and note that when you create arrays in instances, these do not need to be cleaned up when the instance is removed from the game, as they will be removed automatically by the garbage collector on Destroy or Room End. Since arrays are numbered sequentially, this means you can loop through them to perform extra actions too, just like we did to initialize it: Now how do we use an array practically? Exactly the same as we would use a normal variable, as shown in the following examples: The array was only initialised with 5 positions, but we've tried to get position 7 - since arrays are numbered from 0, array is position 7 - therefore the game generates an error and crashes. For example, this will cause the project to crash when run: You should always take care to only access valid array positions, as trying to access a value outside of an array will also give an error. If you already know which items you want to put into the array, you can add comma-separated values between the brackets when declaring the array: However, if you try to access a value in an empty array then you will get an error. This tells GameMaker that the variable ' my_array' is an array, and you can then add values to it at any time in the future. You can also use the GML function array_create() to initialize an array with a fixed size, and you can even create 'empty' arrays with no values, for example: NOTE: The HTML5 export is the exception to the above rule, and when targeting that you should initialise arrays in consecutive order from 0 upwards. The speed difference is negligible for smaller arrays, but larger ones should be optimised as much as possible in this way. This is not strictly necessary but is the optimal way to do it as it will reserve a space in memory that is the exact size of the array, whereas if you initialize an array from 0 upwards, the memory has to be re-allocated for every additional value added (so for a ten-slot array, initialising it in a loop would change the memory allocation ten times). You will notice that the array has been initialised backwards, with the last value being defined first.

Gamemaker studio 2 inventory code#

This simple code will initialize a ten-slot array (from 0 to 9) to hold 0, ie: each slot in the array contains the value 0. This is important to remember as it means that you have to do a certain amount of planning before using arrays, but it is easy enough to initialize one using a repeat loop like this: Initializing an array just means that we give each slot of the array an initial value in preparation for it to be used elsewhere in the project code.

Gamemaker studio 2 inventory how to#

We've shown how to check an array for data, but how do we create the array to start with? First it has to be initialized before we can use it or GameMaker will give us an error. It's worth noting that the contents of an array always start at 0 and can never be negative ! Creating Arrays

So essentially, an array is a container with a number of slots to store values, and each position in the container has a specific number to identify it, which is what we put in the. If you did the following:Īs you can see, you give the array a variable name and then a value in square brackets, where the value is the position in the array to get the data from. The above code gets the value from position 0 of the array ' a' then outputs it to the console, which - based on the contents of the array shown in the image above - would output 125. To access the array you would do something like the following:

This is called a 1D (one-dimensional) array, and as you can see the array is stored in the variable ' a' and contains multiple values. The image below shows a schematic for a basic array: An array is simply a data type that is assigned to a variable, and it can contain not just one value, but multiple values. Before going any further let's clarify what an array actually is and how it's structured.