PHP面向对象详解（三）

<?php
date_default_timezone_set("PRC");
/**
 * 1. 类的定义以class关键字开始,后面跟着这个类的名称.类的名称命名通常每个单词的第一个字母大写.
 * 2. 定义类的属性
 * 3. 定义类的方法
 * 4. 实例化类的对象
 * 5. 使用对象的属性和方法
 */
class Human{
 public $name;
 public $height;
 public $weight;
public function eat($food){
 echo $this->name."'s eating ".$food."<br/>";
 }
}
class Animal{
 public $kind;
 public $gender;
}
class NbaPlayer extends Human{
 // 类的属性的定义
public $name="Jordan";// 定义属性
public $height="198cm";
 public $weight="98kg";
 public $team="Bull";
 public $playerNumber="23";
 private $age="44";
 public $president="David Stern";
 // 类的方法的定义
public function changePresident($newP){
 $this->president=$newP;
 }
 public function run() {
 echo "Running<br/>";
 }
public function jump(){
 echo "Jumping<br/>";
 }
 public function dribble(){
 echo "Dribbling<br/>";
 }
 public function shoot(){
 echo "Shooting<br/>";
 }
 public function dunk(){
 echo "Dunking<br/>";
 }
 public function pass(){
 echo "Passing<br/>";
 }
 public function getAge(){
 echo $this->name."'s age is ".$this->age;
 }
 function __construct($name,$height,$weight,$team,$playerNumber){
 print $name . ";" . $height . ";" . $weight . ";" . $team . ";" . $playerNumber."n";
 $this->name = $name; // $this是php里面的伪变量,表示对象自身
$this->height = $height; // 通过$this可以设置对象的属性值
$this->weight = $weight;
 $this->team = $team;
 $this->playerNumber = $playerNumber;
 }
}
/**
 * 1. 类实例化为对象时使用new关键字,new之后紧跟类的名称和一对括号.
 * 2. 使用对象可以像使用其他值一样进行赋值操作
 */
$jordan = new NbaPlayer("Jordan","198cm","98kg","Bull","23");echo "<br/>";
$james=new NbaPlayer("James","203cm","120kg","Heat","6");echo "<br/>";
// 拜访对象的属性使用的语法是->符号,后面跟着属性的名称
echo $jordan->name."<br/>";
// 调用对象的某个方法使用的语法是->符号,后面跟着方法的名称和一对括号
$jordan->run();
$jordan->pass();
//子类调用父类的方法
$jordan->eat("apple");
//试着调用private,直接以及通过内部的public函数
//$jordan->age;
$jordan->getAge();echo "<br/>";
$jordan->changePresident("Adam Silver");
echo $jordan->president."<br/>";
echo $james->president."<br/>";
 直接从上述例子开始吧.
这里想得到的是,把两位对象的某一个变量同时变掉.――用static
public static $president="David Stern";
 // 类的方法的定义
public static function changePresident($newP){
static::$president=$newP;//这里static换成self更符合规范
}

echo NbaPlayer::$president;echo "<br/>";
NbaPlayer::changePresident("Adam Silver");
echo NbaPlayer::$president;echo "<br/>";

class BaseClass{
 public function test(){
 echo "BaseClass::test called<br/>";
 }
public function test1(){
 echo "BaseClass::test1 called<br/>";
 }
}
class ChildClass extends BaseClass{
 public function test(){
 echo "ChildClass::test called<br/>";
 }
}
$obj=new ChildClass();
$obj->test();

//具体对象,连接到接口
class Human implements ICanEat{
public function eat($food){
 echo "Human eating ".$food.".<br/>";
 }
}
$obj=new Human();
$obj->eat("shit");

interface ICanEat{
 public function eat($food);
}
//具体对象,连接到接口
class Human implements ICanEat{
public function eat($food){
 echo "Human eating ".$food.".<br/>";
 }
}
class Animal implements ICanEat{
 public function eat($food){
 echo "Animal eating ".$food.".<br/>";
 }
}
$obj=new Human();
$obj->eat("shit");
$monkey=new Animal();
$monkey->eat("banana");

interface ICanPee extends ICanEat{
 public function pee();
}
class Demon implements ICanPee{
 public function pee(){
 echo "Can demon pee?";
 }
 public function eat($food){
 echo "Can demon eat ".$food;
 }
}
$ghost=new Demon();
$ghost->pee();
$ghost->eat("shit");