Regular expression example 1

 <?php  
      // type of regular expression  
      //posix style regular exrpession  
      //pcre style regular expression  
      $sentence = "I lob to have tea but some time I prefer coffee";  
      if(ereg("lob",$sentence))  
      {  
           echo "regular expression is true";  
      }  
      else  
      {  
           echo "regular expression is false";  
      }  
 ?>