<?php include "C:/xampp/htdocs/training/php/OOP/myFunction/myStrlen_function.php"; include "C:/xampp/htdocs/training/php/OOP/myFunction/myStringRev.php"; include "C:/xampp/htdocs/training/php/OOP/myFunction/uppercase.php"; include "C:/xampp/htdocs/training/php/OOP/myFunction/lowercase.php"; class my_string { public $string = ""; function str_len() { return my_strlen($this->string); } } $string1 = new my_string(); $string1->string = "my name is poly"; echo $string1->str_len(); //echo "The string reverse is : ", $string1->str_rev(); //echo "The uppercase string is : ", $string1->upper(); //echo "The lowercase string is : ", $string1->lower();