PHP5 OOP新手快速入门例子

PHP5 的OOP是个好东西，最近找了些小资料给新手培训和给朋友看，还是老外的东西好，例子短小，有OOP基础的话，一看就
明白了

  1）基本的类和实例
   

<?php
class Animal
{
var $name;
function set_name($text)
{
$this->name = $text;
}
function get_name()
{
return $this->name;
}
}
$lion = new Animal;
$lion->set_name("Leo");
echo "The name of your new lion is ", $lion->name, ".";
?>

2) 加上些访问控制符，如private

<?php
class Animal
{
private $name;
function set_name($text)
{$this->name = $text;}
function get_name()
{return $this->name;}
}
$lion = new Animal;
$lion->set_name("Leo");
echo "The name of your new lion is ", $lion->name, ".";
?>

由于用了privae,所以这里是出错了，要用get_name去访问

3）构造函数

<?php
class Animal
{
var $name;
function __construct($text)
{
$this->name = $text;
}
function set_name($text)
{
$this->name = $text;
}
function get_name()
{
return $this->name;
}
}
$lion = new Animal("Leo");
echo "The name of your new lion is ", $lion->get_name(), ".";
?>
用 _ _construct()做构造函数( 注意，是两个紧跟着的_)

4  使用继承

<?php
class Animal
{
var $name;
function set_name($text)
{
$this->name = $text;
}
function get_name()
{
return $this->name;
}
}
class Lion extends Animal
{
var $name;
function roar()
{
echo $this->name, " is roaring!<BR>";
}
}
echo "Creating your new lion...<BR>";
$lion = new Lion;
$lion->set_name("Leo");
$lion->roar();
?>

5   Overriding

<?php
class animal
{
var $name;
function set_name($text)
{
$this->name = $text;
}
function get_name()
{
return $this->name;
}
}
class Lion extends Animal
{
var $name;
function roar()
{
echo $this->name, " is roaring!<BR>";
}
function set_name($text)
{
$this->name = strtoupper($text);
}
}
echo "Creating your new lion...<BR>";
$lion = new Lion;
$lion->set_name("Leo");
$lion->roar();
?>

输出：LEO is roaring

这时子类覆盖了父类的set_name方法了

6  访问父类中的被覆盖的方法

<?php
class Animal
{
var $name;
function set_name($text)
{
$this->name = $text;
}
function get_name()
{
return $this->name;
}
}
class Lion extends Animal
{
var $name;
function roar()
{
echo $this->name, " is roaring!<BR>";
}
function set_name($text)
{
Animal::set_name($text);
}
}
echo "Creating your new lion...<BR>";
$lion = new Lion;
$lion->set_name("Leo");
$lion->roar();
?>