Pls help me understand oop in php better ? its confusing...pls ?

[jd2007]

here are my questions:

1. What are the things that a class should contain ? i know methods and properties ... what are constructors and destructors ?

2. What should constructors and destructors contain ?

3. What are the functions/built in stuff i can use to do oop ?

4. Where can i find a informative tutorial which doesn't speak of dogs and cats but real php stuff ?

[pranav_kavi]

These links ll help u,

 

http://www.phpfreaks.com/tutorial_cat/19/Object-Oriented-Programming.php

OR

http://www.codewalkers.com/c/a/Programming-Basics/Beginning-Object-Oriented-Programming-in-PHP/

[GingerRobot]

Until recently, i'd hardly used OOP at all. At the moment, im trying to make a graphical calculator(it was the 1st competition, but i didn't have the time, or really the knowledge, to do it back then). I decided to attempt this in an OO manner.

 

Perhaps the way i have structured my code would help you:

 

<?php
class graph(){
//list all the attributes of the class - sizes and scales for x and y, the image handler etc
function __construct($data){//i pass in an array of data to set up the image
	//the constructor creates the image and ouputs the correct header. It sets the attributes
	//of the class from the data passed to it
}
function colours($colour){
	//takes a colour in a string and passes back a colour identifier
}
function drawaxis(){
	//this function drax axis on the graph
}
function plot_equation(){
	//plots the equation we are drawing
}
function parse_equation{
	//parses a string as an equation to make it useable - this is the bit im working on now
}
function __destruct(){
	//outputs the image
}
}
?>

 

The idea behind my usage of constructors and destuctors is that i have put everything that needs to be set up before the class can be used in the contructor - you cant draw the axis/plot an equation until you've created an image etc. The destructor is used to output the image after the last call to the class.

[jd2007]

thank you so much ginger robot for taking your time to write me that informative example...it helps a lot...

[GingerRobot]

I hope it does help. I do agree that it is hard to find good tutorials and examples of using OOP. I find that things get over-simplified for the sake of example, and end up becoming pointless.