[RESOLVED] Help with Classes and Functions

RediXe

Fatal error: Non-abstract method myTest::testTest() must contain body in C:\xampp\htdocs\Calc\functions.php on line 8

I can't figure out what is killing this:

index.php

<?PHP
require 'functions.php';
?>

<html>
<body>

<?PHP
$test = new myTest();
$test->testTest();
?>

functions.php

<?PHP
class myTest
{
private $a = 'default';

public function testTest() {
echo "Test: " . $this->a;
}
}
?>

phaseonemedia

Ok, first off, you need to change $this-a to $this->a.
Second, when inheriting from an abstract class, all methods marked abstract in the parent's class declaration must be defined by the child; additionally, these methods must be defined with the same (or a less restricted) visibility. For example, if the abstract method is defined as protected, the function implementation must be defined as either protected or public, but not private.

RediXe

Thanks for the response but it went a little over my head. The - was just a typo. I edited to the OP to make it shows corrections. Are you trying to say the variable $a needs to be protected instead private?

phaseonemedia

Here,

<?PHP
class myTest {
  function myTest() {
    var $a = "default";
  }
  function testTest() {
    echo "Test: $this->a";
  }
}
?> 



<?PHP
require 'functions.php';
?>

<html>
<body>

<?PHP
$test = new myTest();
$test->testTest();
?>

you may find this usefull as well...
http://usphp.com/manual/en/language.oop5.paamayim-nekudotayim.php

hope it helps.

RediXe

So why do I have to declare the var $a inside a function? I am having trouble seeing the purpose in doing so.

EDIT:

Taken from the manual:

<?php
class SimpleClass
{
    // member declaration
    public $var = 'a default value';

// method declaration
public function displayVar() {
    echo $this->var;
}
}

?>

the only real difference is the var is public instead of private or protected.

phaseonemedia

simulates a private scope

RediXe

Seems odd but if it works then I guess that is fine. Can I achieve the same effect with declaring the var in a constructor? (I new to classes still so go easy on me)

EDIT:

Just noticed the var a is declared in a function with the same name as the class. Is that the constructor or something similar?

EDIT 2:

I must be blind today. 🙁 Just saw you link, checking it out now.

halojoy

RediXe wrote:
Thanks for the response but it went a little over my head. The - was just a typo. I edited to the OP to make it shows corrections. Are you trying to say the variable $a needs to be protected instead private?

As your code is NOW, it is fully correct and working.
I have tested it on my server.
You use a private variable and display it inside a function within your class
and this always works, even if function is public.

But of course this will not work:
( not with private, not with protected variables )

<?php
require( './includes/myTest.class.php');

$test = new myTest();
echo $test->a;  // should give error, as variable is private

?>

The Class. ./includes/myTest.class.php :
<?php

class myTest
{
    private $a = 'default';

public function testTest() {
    echo "Test: " . $this->a;
}
}

?>
You original test code works perfectly
<?php
require( './includes/myTest.class.php');
?>
<html>
<body>

<?php
$test = new myTest();
$test->testTest();  // works alright

?>
Some good links, with code examples and PHP Classes:

PHP 101 (PART 7): The Bear Necessities [August 07, 2004]
A gentle introduction to object oriented programming in PHP 4 and PHP 5.
http://devzone.zend.com/node/view/id/638

And of course all articles WITH examples in The PHP Manual
at PHP Homepage:
http://docs.php.net/manual/en/language.oop5.php
Classes and Objects (PHP 5)
Table of Contents
* The Basics
* Autoloading Objects
* Constructors and Destructors
* Visibility
* Scope Resolution Operator (::)
* Static Keyword
* Class Constants
* Class Abstraction
* Object Interfaces
* Overloading
* Object Iteration
* Patterns
* Magic Methods
* Final Keyword
* Object cloning
* Comparing objects
* Reflection
* Type Hinting
* Late Static Bindings[/QUOTE]
regars 🙂
halojoy

phaseonemedia

yessum, thats what it is, your declaring it in the constructor.

What is not mentioned in the manual is that you can use "self" to force object hinting on a method of the implementing class:

Consider the following interface:

<?php
interface Comparable
{function compare(self $compare);}
?>

Which is then implemented:

<?php

class String implements Comparable
{
    private $string;
    function __construct($string)
    {$this->string = $string;}
    function compare(self $compare)
    {return $this->string == $compare->string;}
}

class Integer implements Comparable
{
    private $integer;
    function __construct($int)
    {$this->integer = $int;}
    function compare(self $compare)
    {return $this->integer == $compare->integer;}
}

?>

Comparing Integer with String will result in a fatal error, as it is not an instance of the same class:

<?php
$first_int = new Integer(3);
$second_int = new Integer(3);
$first_string = new String("foo");
$second_string = new String("bar");

var_dump($first_int->compare($second_int)); // bool(true)
var_dump($first_string->compare($second_string)); // bool(false)
var_dump($first_string->compare($second_int)); // Fatal Error
?>

phaseonemedia

ok, yea, maybe that one was a little over the top and totally not neccessary, but hey, im really bored right now.

RediXe

You guys are AWESOME!

halojoy

phaseonemedia wrote:
ok, yea, maybe that one was a little over the top ...

phaseonemedia,
remember, we have many readers that are guests and do not post.
Quite a few of those, will already have COPY & PASTE your code
and someone will even have use of some new knowledge you posted.

RediXe, you got what you wanted

confirmation being on the right way with your PHP Class Programming

Guest, who read this, you may have got something useful, I am almost sure!

Me, halojoy & phaseonemedia,
got what we like:
A nice feeling ....that we are
... useful to have around here
... and once in a while, even real PHP-problem solvers 🙂

regars 🙂
freindly halojoy