Syntax help - defining a number of empty array KEYS

[s_shrum]

I want to define an array in which only the keys are defined. Short of doing:

$templates_array['this'] = "";
$templates_array['that'] = "";
$templates_array['foo'] = "";
$templates_array['bar'] = "";

Is there a better way, syntactically? Maybe something like:

$templates_array[('this', 'that', 'foo', 'bar')] = "";

TIA

[Weedpacket]

Originally posted by s_shrum
I want to define an array in which only the keys are defined. Short of doing:

$templates_array['this'] = "";
$templates_array['that'] = "";
$templates_array['foo'] = "";
$templates_array['bar'] = "";

Is there a better way, syntactically? Maybe something like:

$templates_array[('this', 'that', 'foo', 'bar')] = "";

TIA

I find myself asking why, since with an associative array, if an array element doesn't exist, its key shouldn't exist...
$keys = array('this','that','foo','bar');
foreach($keys as $key)$templates_array[$key]=null;