Question: How do you determine the length of an array in GameMaker?

Answer

In GameMaker, you can determine the length of a one-dimensional array using the built-in array_length_1d function. This function returns the size of the array in terms of the number of elements it contains.

Here is a simple code example illustrating how to use array_length_1d:

// Create a one-dimensional array
var myArray = [10, 20, 30, 40, 50];

// Get the length of the array
var length = array_length_1d(myArray);

// Display the length
show_debug_message("The length of the array is: " + string(length));

For two-dimensional arrays, GameMaker also offers the functions array_height_2d and array_width_2d, which return the height (number of rows) and the width (number of columns) respectively. Below is an example of how to find the size of a two-dimensional array:

// Create a two-dimensional array
var my2DArray;
my2DArray[0,0] = 11; my2DArray[0,1] = 12;
my2DArray[1,0] = 21; my2DArray[1,1] = 22;

// Get the height and width of the array
var height = array_height_2d(my2DArray);
var width = array_width_2d(my2DArray);

// Display the dimensions
show_debug_message("The array has " + string(height) + " rows and " + string(width) + " columns.");

Note that in GameMaker Studio 2.3 and above, arrays are more dynamic and can have varying lengths for each index when dealing with two-dimensional arrays. Therefore, you might need to loop through each "row" to get the length of each "column" if they are not consistent.