PHP: Can't use inheritance. It won't find the class

Question

I reached the cap about inheritance but I can't use them, even when I try to use the examples from the book I'm learning. Even though all the files are on the same folder, the error is:

"Fatal error: Class 'mother' not found in C:\Program Files (x86)\EasyPHP-Devserver-16.1\eds-www\Learning\classes\son.php on line 2"

Let me show a exemple I created to explain.

FILE: mother.php:

    <?php
    class mother
    {
       public $word= "Hello!!!";

       function printWord()
       {
         echo $word;   
       }
     }
     ?>

FILE: son.php:

<?php 
  class son extends mother
   {
     function printWord()
     {
      parent::printWord();
     }
   }  
?>

FILE: test.php:

<?php
include 'son.php';
$test = new son();
$test->printWord();
?>

Results in:

ERROR: Fatal error: Class 'mother' not found in C:\Program Files (x86)\EasyPHP-Devserver-16.1\eds-www\Learning\classes\son.php on line 2

Why is this happening? Why it won't find the class if it is on the same folder ?!

Answer 1

You need to include the mother.php too. Otherwise it can't find the class as the error states.

Naive example:

test.php

<?php
include 'mother.php'
include 'son.php';
$test = new son();
$test->printWord();
?>

But there is even a better way

son.php

<?php 
  require_once 'mother.php'
  class son extends mother
   {
     function printWord()
     {
      parent::printWord();
     }
   }  
?>