Unary test -v on an array element

In bash, the conditional expression with the unary test -v myvariable tests wether the variable myvariable has been set. Note that myvariable should not be expanded by prefixing it with a dollar, so **not** $myvariable. Now I find that for array elements the conditional expression -v myarray[index] works well too, without the full expansion syntax ${myarray[$index]}. Try this: myarray=myvalue for i in 1 2 3 do [ -v myarray\[i] ] && echo element $i is set done (note the escape \[ to prevent globbing, as alternative to using quotes) gives the desired output: element 2 is set **Question** Is this behaviour safe to use *aka* is this documented behaviour? **Addendum** After reading the answer https://unix.stackexchange.com/a/677920/376817 of Stéphane Chazelas, I expanded my example: myarray=val myarray=val myarray=val myarray=val myarray=val myarray="" myarray="" unset myarray myarray myarray touch myarray4 myarrayi myarray4=val myarrayi=val then for i in {0..7}; do [ -v myarray\[i] ] && echo element $i is set; done gives element 1 is set element 2 is set element 6 is set Without quoting or escaping the index expression [i] : for i in {0..7}; do [ -v myarray[i] ] && echo element $i is set; done gives element 0 is set element 1 is set element 2 is set element 3 is set element 4 is set element 5 is set element 6 is set element 7 is set The same with the variable myarrayi unset : unset myarrayi for i in {0..7}; do [ -v myarray[i] ] && echo element $i is set; done gives %nothing% And finally with expansion of the index as $i (still without quoting or escaping the bracket) : for i in {0..7}; do [ -v myarray[$i] ] && echo element $i is set; done it gives element 1 is set element 2 is set element 4 is set because ls -l myarray* shows -rw-rw-r-- 1 me us 0 nov 17 15:37 myarray4 -rw-rw-r-- 1 me us 0 nov 17 15:37 myarrayi