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();

?>