$var = 'abcdef'; if (strlen($var)<0); { } else { } 

This is a simple example. Hope it helps.

$var = 'abcdef'; if(isset($var)) { if (strlen($var) > 0);  {  //do something, string length greater than zero  }  else  {  //do something else, string length 0 or less  } } 

This is a simple example. Hope it helps.

edit: added isset in the event a variable isn't defined like above, it would cause an error, checking to see if its first set at the least will help remove some headache down the road.