You can use 1- and 2-dimensional arrays in GML. Simply put the
index between square brackets for a 1-dimensional array, and the
two indices with a comma between them for 2-dimensional arrays. At
the moment you use an index the array is generated. Each array runs
from index 0. So be careful with using large indices because memory
for a large array will be reserved. Never use negative indices. The
system puts a limit of 32000 on each index and 1000000 on the total
size. So for example you can write the following:
{
a[0] = 1;
i = 1;
while (i < 10) { a[i] = 2*a[i-1]; i += 1;}
b[4,6] = 32;
}