PHP中的面向对象实践
基本实践
高级实践
特殊实践
类的概念
实例化的概念
构造函数
析构函数
数据访问
对象引用的概念
类的概念
类
? 物以类聚，把具有相似特性的对象归类到一个类中
? 类定义了这些相似对象拥有的相同的属性和方法
? 类是相似对象的描述，称为类的定义，是该类对象的蓝图或者原型
? 类的对象称为类的一个实例(Instance) //类画了一个框架，对象把框架塞满
? 类的属性和方法统称为类成员
例子
? NBA球员就是一个类的定义(Class Definition)
? 乔丹、詹姆斯、科比称为类的实例(Instance)
NBA球员
+姓名
+身高
+体重
+所在球队
+球员号码
------------
+跑步()
+跳跃()
+运球()
+投篮()
+扣篮()
+传球()
类的实例化(instantiate)
案例
类和类的实例化案例
? 如何定义一个类
? 如何实例化类的
对象? 如何调用类的方法
? 构造函数
? 析构函数
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 | <?php
class NbaPlayer{
public $name="Jordan";
public $height="198cm";
public $weight="98kg";
public $team="Bull";
public $playerNumber="23";
public function run(){
echo "Running\n";
}
public function jump(){
echo "Jumping\n";
}
public function dribble(){
echo "Dribbling\n";
}
public function shoot(){
echo "Shooting\n";
}
public function dunk(){
echo "Dunking\n";
}
public function pass(){
echo "Passing\n";
}
}
$jordan = new NbaPlayer();
echo $jordan->name."\n";
$jordan->dribble();
$jordan->pass();
?>
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Output:
Jordan
Dribbling
Passing
构造函数
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 | <?php date_default_timezone_set("PRC");
class NbaPlayer{
public $name="Jordan";
public $height="198cm";
public $weight="98kg";
public $team="Bull";
public $playerNumber="23";
function __construct($name,$height,$weight,$team,$playerNumber){
echo "In NbaPlayer Constructor\n";
$this->name=$name;
$this->height=$height;
$this->weight=$weight;
$this->team=$team;
$this->playerNumber=$playerNumber;
}
public function run(){
echo "Running\n";
}
public function jump(){
echo "Jumping\n";
}
public function dribble(){
echo "Dribbling\n";
}
public function shoot(){
echo "Shooting\n";
}
public function dunk(){
echo "Dunking\n";
}
public function pass(){
echo "Passing\n";
}
}
$jordan = new NbaPlayer("Jordan","198cm","98kg","Bull","23");
echo $jordan->name."\n";
$jordan->dribble();
$jordan->pass();
$james= new NbaPlayer("James","203cm","120kg","Heat","6");
echo $james->name;
echo $james->height;
echo $james->weight;
echo $james->team;
echo $james->playerNumber;
?>
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Output:
In NbaPlayer Constructor
Jordan
Dribbling
Passing
In NbaPlayer Constructor
James
203cm
120kg
Heat
6
析构函数
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 | <?php date_default_timezone_set("PRC");
class NbaPlayer{
public $name="Jordan";
public $height="198cm";
public $weight="98kg";
public $team="Bull";
public $playerNumber="23";
function __construct($name,$height,$weight,$team,$playerNumber){
echo "In NbaPlayer Constructor\n";
$this->name=$name;
$this->height=$height;
$this->weight=$weight;
$this->team=$team;
$this->playerNumber=$playerNumber;
}
function __destruct(){
echo "Destroying ".$this->name."<br>";
}
public function run(){
echo "Running\n";
}
public function jump(){
echo "Jumping\n";
}
public function dribble(){
echo "Dribbling\n";
}
public function shoot(){
echo "Shooting\n";
}
public function dunk(){
echo "Dunking\n";
}
public function pass(){
echo "Passing\n";
}
}
$jordan = new NbaPlayer("Jordan","198cm","98kg","Bull","23");
echo $jordan->name."\n";
$jordan->dribble();
$jordan->pass();
$james= new NbaPlayer("James","203cm","120kg","Heat","6");
echo $james->name;
$james=null;
echo "From now on James will not be used. <br>";
?>
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Output:
In NbaPlayer Constructor
Jordan
Dribbling
Passing
In NbaPlayer Constructor
James
Destroying James
From now on James will not be used.
Destroying Jordan
对象引用的基本概念
对象引用赋值
詹姆斯是一个对象。
$james就是对象的引用，直接指向詹姆斯这个对象。
$james1和$james是两个独立的引用，$james1这个对象的引用直接指向詹姆斯这个对象。
$james2是一个指向$james这个对象引用的对象引用(有点拗口)，没有直接指向詹姆斯这个对象。$james2是通过$james这个对象引用去指向詹姆斯这个对象的
现在直接指向对象詹姆斯的对象的引用有两个，即$james和$james1。而$james2是$james的映像。
示例一：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 | <?php date_default_timezone_set("PRC");
class NbaPlayer{
public $name="Jordan";
public $height="198cm";
public $weight="98kg";
public $team="Bull";
public $playerNumber="23";
function __construct($name,$height,$weight,$team,$playerNumber){
echo "In NbaPlayer Constructor\n";
$this->name=$name;
$this->height=$height;
$this->weight=$weight;
$this->team=$team;
$this->playerNumber=$playerNumber;
}
function __destruct(){
echo "Destroying ".$this->name."<br>";
}
public function run(){
echo "Running\n";
}
public function jump(){
echo "Jumping\n";
}
public function dribble(){
echo "Dribbling\n";
}
public function shoot(){
echo "Shooting\n";
}
public function dunk(){
echo "Dunking\n";
}
public function pass(){
echo "Passing\n";
}
}
$jordan = new NbaPlayer("Jordan","198cm","98kg","Bull","23");
echo $jordan->name."\n";
$jordan->dribble();
$jordan->pass();
$james= new NbaPlayer("James","203cm","120kg","Heat","6");
echo $james->name;
$james1=$james;
$james=null;
echo "From now on James will not be used. <br>";
?>
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Output:
In NbaPlayer Constructor
Jordan
Dribbling
Passing
In NbaPlayer Constructor
James
From now on James will not be used.
Destroying James
Destroying Jordan
示例二：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 | <?php date_default_timezone_set("PRC");
class NbaPlayer{
public $name="Jordan";
public $height="198cm";
public $weight="98kg";
public $team="Bull";
public $playerNumber="23";
function __construct($name,$height,$weight,$team,$playerNumber){
echo "In NbaPlayer Constructor\n";
$this->name=$name;
$this->height=$height;
$this->weight=$weight;
$this->team=$team;
$this->playerNumber=$playerNumber;
}
function __destruct(){
echo "Destroying ".$this->name."<br>";
}
public function run(){
echo "Running\n";
}
public function jump(){
echo "Jumping\n";
}
public function dribble(){
echo "Dribbling\n";
}
public function shoot(){
echo "Shooting\n";
}
public function dunk(){
echo "Dunking\n";
}
public function pass(){
echo "Passing\n";
}
}
$jordan = new NbaPlayer("Jordan","198cm","98kg","Bull","23");
echo $jordan->name."\n";
$jordan->dribble();
$jordan->pass();
$james= new NbaPlayer("James","203cm","120kg","Heat","6");
echo $james->name;
$james1=$james;
$james2=&james;
$james=null;
$james1=null;
echo "From now on James will not be used. <br>";
?>
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Output:
In NbaPlayer Constructor
Jordan
Dribbling
Passing
In NbaPlayer Constructor
James
Destroying James
From now on James will not be used.
Destroying Jordan
以上就介绍了PHP面向对象编程——基本实践DAY 2，包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。
