Is this right? test -v $hash{defined_value} == false?

[Linda Walsh]

 set -A hash
 hash=([defined_value]=22)
 echo ${hash[defined_value]}

22

 [[ -v ${hash[defined_value]} ]] && echo pass
 [[ -v ${hash[defined_value]} ]] || echo fail

fail

[[ -v {hash[defined_value]} ]] || echo fail

fail

[[ -v hash[defined_value] ]] || echo fail

fail
[[ -v \${hash[defined_value]} ]] || echo fail
fail

 echo $BASH_VERSION

4.2.45(1)-release


How do I test if a value is defined in a hash?

This seems more messy and isn't -v supposed
to help clean up such things?

 [[ ${hash[defined_value]:-""} ]] || echo fail  #it passes
 [[ ${hash[defined_value1]:-""} ]] || echo fail

fail

So why no '-v'??  :-(