#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation, either version 3 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
foo[0]=a
foo[1]=b

[[ -v foo[1] ]] && echo foo index 1: ok
[[ -v foo[2] ]] || echo foo index 2: ok

[[ -v foo ]] && echo foo: implicit reference to element 0: ok

typeset -i foo

[[ -v foo[1] ]] && echo foo: arithmetic evaluation: ok

typeset -a bar
bar[1]=set

[[ -v bar ]] || echo bar: array with element zero unset: ok
[[ -v bar[0] ]] || echo bar: element zero: ok

typeset -a qux
[[ -v qux ]] || echo qux: unset array: ok
[[ -v qux[0] ]] || echo qux: unset array element 0: ok