4 [[ -v foo[1] ]] && echo foo index 1: ok
5 [[ -v foo[2] ]] || echo foo index 2: ok
7 [[ -v foo ]] && echo foo: implicit reference to element 0: ok
11 [[ -v foo[1] ]] && echo foo: arithmetic evaluation: ok
16 [[ -v bar ]] || echo bar: array with element zero unset: ok
17 [[ -v bar[0] ]] || echo bar: element zero: ok
20 [[ -v qux ]] || echo qux: unset array: ok
21 [[ -v qux[0] ]] || echo qux: unset array element 0: ok