posted 15 years ago
Let's check out what each array contains. Initially:
a1 = {null}
a2 = {{null}, {null}}
a3 = {{{null, null, null}, {null, null, null}, {null, null, null}}, {{null, null, null}, {null, null, null}, {null, null, null}}, {{null, null, null}, {null, null, null}, {null, null, null}}}
a1 then becomes {A}
a2 becomes {{A}, {A}}
a3 becomes {{{A}, {A}}, {{A}, {A}}, {{A}, {A}}}
a3 is now no longer an A[3][3][3] but an A[3][2][1]. As such, there is no a3[2][2]. The highest indexes you can get is a3[2][1][0].