first of all, ImageJ macro is compared to Python a quite limited language. It’s made for calling some ImageJ operations in a row, not for building complex software. If you plan to build something bigger with ImageJ, I’d recommend using Fijis Jython. There is a nice online tutorial by @albertcardona.
Regarding your questions: I’m not aware of any
newArray Method works like this:
emptyArray = newArray(0);
arrayWithThreeElements = newArray(3);
print("Array with three empty elements:")
arrayWithFourElements = newArray(1,2,3,4);
print("Array with four elements:")
longArray = Array.concat(arrayWithThreeElements, arrayWithFourElements);
print("Array with seven elements:")
There is also some explanation of numeric variables, strings and arrays online:
Let us know if that helps!