Código PHP:
function valida($name){
if(strlen($name) < 4){ return false;}
elseif(!preg_match("/^[a-zA-Z]+$/", $name)) { return false; }
else {return true;}
}
$ec="";
$array = array(0 => "", 1 => "jesus", 2 => "pedro", 3 => "pablo");
$c=count($array);
for($x=0;$x>$c;$x++){
if(valida($array[$x])==true){ echo 'Hay un campo vacio'; }
}