syntax - PHP $$var['index'] = something; fails, although I thought it would work just like $$var = something; does -

i trying use $$ syntax in php accessing arrays can put name of variable inside variable , access variable.

i have used syntax many times before in different ways, surprise didn't work me , lost lot of time on it.

here sample code replicate problem:

$test=array( 'a'=>array(array(1,2,3),array(4,5,6),array(7,8,9)) );  $var = 'test'; var_dump($$var); var_dump($$var['a']); 

the line var_dump($$var) works expected, i'm getting warning: illegal string offset 'a' @ line var_dump($$var['a']); , var_dump prints null

why doesn't work? doing wrong here? there work around if syntax not supported arrays?

your $$var['a'] equivalent ${$var['a']}. not ${$var}['a']. latter being workaround syntax looking for.

quoting php manual on variable variables:

in order use variable variables arrays, have resolve ambiguity problem. is, if write $$a[1] parser needs know if meant use $a[1] variable, or if wanted $$a variable , [1] index variable. syntax resolving ambiguity is: ${$a[1]} first case , ${$a}[1] second.

see http://codepad.org/lr7qjygx