Date: 10/15/07 (PHP Community)    Keywords: no keywords

Suppose I have an associative array that looks like this:
$arr['alpha_1'] = 'some value';
$arr['alpha_3'] = 'some value';
$arr['alpha_4'] = 'some value';
$arr['beta_2'] = 'some value';
$arr['beta_4'] = 'some value';
$arr['beta_6'] = 'some value';
$arr['gamma_1'] = 'some value';
$arr['gamma_5'] = 'some value';
$arr['gamma_6'] = 'some value';
$arr['gamma_7'] = 'some value';

Let's assume that the array is reasonably large (hundreds of entries).

Is there an efficient way of getting all the items whose key starts with 'beta'? (without doing a foreach/strncmp loop?)

Thanks in advance!

P.S: The array is not sorted.

Source: http://community.livejournal.com/php/590552.html