Can you index an array with a long int?

Question

Is it somehow possible to use a long int to index an array? Or is this not allowed?

What I mean is bellow in the code.

long x = 20;
char[] array = ne         


        

Answer 1

Technically you can have such a structure using Unsafe class. with it you can allocate as much memory as you want (as you have actually). To be noted that this is native memory and not heap memory. Because of this, there are downsides as compared to typical arrays, though: the memory isn't garbage collected (you'll need to manually deallocate memory) and there aren't bound checks so without being careful you can have seg fault and crash your JVM.

See example here, at Big Array section: http://mishadoff.com/blog/java-magic-part-4-sun-dot-misc-dot-unsafe/

Also there are rumors that future versions of JVM and the language will have support arrays of size long.