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PHP -- 面向对象

PHP – 面向对象

函数调用
有 __clone 和无 __clone
继承
protected
static
final
const
后期绑定, 又叫延迟绑定
单例模式 instanceof
魔术方法
重载覆盖
魔术常量
抽象类和接口
命名空间
其他对象方法
自动加载
TODO SPL 函数

函数调用

<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">test</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">f1</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'you call me!'</span>;    }    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">f2</span>() {        f1();    }}<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">test</span>();<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t</span>-><span style="color: #ffffff; background-color: #000000;">f2</span>();                  <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">报错</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">public function f2() {  // 正确</span><span style="color: #ff7f24;">//     </span><span style="color: #ff7f24;">self::f1();</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">}</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">public function f2() {  // 正确</span><span style="color: #ff7f24;">//     </span><span style="color: #ff7f24;">static::f1();</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">}</span>

有 clone 和无 clone

一个值得注意的地方 __clone() cannot accept any arguments

直接赋值 (复制), 不会产生新的对象

<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">test</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">__construct</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'ok'</span>;    }    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">__destruct</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'fail'</span>, <span style="color: #ffa07a;">'<br>'</span>;    }}<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">a</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">test</span>();<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">b</span> = <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">a</span>;               <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">指向同一个内存空间</span><span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'<hr>'</span>;<span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">ok</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">-----</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">fail</span>

clone 会生成一个新的对象, 但不会调用构造函数

<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">test</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">__construct</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'ok'</span>;    }    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">__destruct</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'fail'</span>, <span style="color: #ffa07a;">'<br>'</span>;    }}<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">a</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">test</span>();<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">b</span> = <span style="color: #00ffff;">clone</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">a</span>;         <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">指向不同的 内存空间</span><span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'<hr>'</span>;<span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">ok</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">---------------</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">fail</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">fail</span>

__clone 调用析构函数

<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">test</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">__construct</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'ok'</span>, <span style="color: #ffa07a;">'<br>'</span>;    }    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">__destruct</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'fail'</span>, <span style="color: #ffa07a;">'<br>'</span>;    }    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">__clone</span>() {        <span style="color: #00ffff;">return</span> <span style="color: #00ffff;">self</span>::__construct();    }}<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">a</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">test</span>();<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">b</span> = <span style="color: #00ffff;">clone</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">a</span>;         <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">指向不同的 内存空间</span><span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'<hr>'</span>;<span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">ok</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">ok</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">-----</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">fail</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">fail</span>

继承

<span style="color: #b0c4de;"><?php</span><span style="color: #00ffff;">class</span> <span style="color: #98fb98;">A</span> {    <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">foo</span>() {        <span style="color: #00ffff;">if</span> (<span style="color: #00ffff;">isset</span>(<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #7fffd4;">this</span>)) {            <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'this is defined ('</span>,  get_class(<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #7fffd4;">this</span>), <span style="color: #ffa07a;">')'</span>, <span style="color: #ffa07a;">'<br>'</span>;        } <span style="color: #00ffff;">else</span> {            <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'this is not defined'</span>, <span style="color: #ffa07a;">'<br>'</span>;        }    }}<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">B</span> {    <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">bar</span>() {        <span style="color: #7fffd4;">A</span>::foo();    }}<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">a</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">A</span>();                   <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">this 变成 A</span><span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">a</span>-><span style="color: #ffffff; background-color: #000000;">foo</span>();<span style="color: #7fffd4;">A</span>::foo();<span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">this is defined (A)</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">this is not defined</span><span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">b</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">B</span>();                   <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">this 变成 B</span><span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">b</span>-><span style="color: #ffffff; background-color: #000000;">bar</span>();<span style="color: #7fffd4;">B</span>::bar();<span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">this is defined (B)</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">this is not defined</span>

继承的时候权限只能越来越大, 不能变小

<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">A</span> {    <span style="color: #00ffff;">protected</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">a</span> = <span style="color: #ffa07a;">'a'</span>;    <span style="color: #00ffff;">protected</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">f</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #7fffd4;">this</span>-><span style="color: #eedd82;">a</span>, <span style="color: #ffa07a;">'<br>'</span>;    }}<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">B</span> <span style="color: #00ffff;">extends</span> <span style="color: #98fb98;">A</span>{    <span style="color: #00ffff;">private</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">f</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #7fffd4;">this</span>-><span style="color: #eedd82;">a</span>, <span style="color: #ffa07a;">'<br>'</span>;    }}<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">b</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">B</span>();<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">b</span>-><span style="color: #ffffff; background-color: #000000;">f</span>();                  <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">报错</span>

protected

<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">A</span> {    <span style="color: #00ffff;">protected</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">a</span> = <span style="color: #ffa07a;">'a'</span>;    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">f</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #7fffd4;">this</span>-><span style="color: #eedd82;">a</span>, <span style="color: #ffa07a;">'<br>'</span>;    }}<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">B</span> <span style="color: #00ffff;">extends</span> <span style="color: #98fb98;">A</span>{    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">f</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #7fffd4;">this</span>-><span style="color: #eedd82;">a</span>, <span style="color: #ffa07a;">'<br>'</span>;    }}<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">b</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">B</span>();                   <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">可以继承 protected</span><span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">b</span>-><span style="color: #ffffff; background-color: #000000;">f</span>();

static

static 变量
所有实例化的实例化的类共享的变量, 其中一个改变了, 其他的也跟着改变

class stu {    public static $fee;    function f($fee) {        self::$fee += $fee;    }}

static 方法
不可以操作 $this 变量, 使用 static 方法的情景, 一般的原则是某个方法中不包含 $this 变量

calss stu {    static function func1() {        static::func2();    }    static function func2() {         ...    }}

调用: stu::func2();, stu::func1();

final

使用 finnal 的场景:

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出于安全的考虑, 某个类的方法不允许被修改
不希望被其他的类继承

final 不能修饰成员属性 (变量)

final 方法, 表示此方法不能被重写

<span style="color: #b0c4de;"><?php</span><span style="color: #00ffff;">class</span> <span style="color: #98fb98;">BaseClass</span> {   <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">test</span>() {       <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">"BaseClass::test() called\n"</span>;   }   <span style="color: #00ffff;">final</span> <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">moreTesting</span>() {       <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">"BaseClass::moreTesting() called\n"</span>;   }}<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">ChildClass</span> <span style="color: #00ffff;">extends</span> <span style="color: #98fb98;">BaseClass</span> {   <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">moreTesting</span>() {       <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">"ChildClass::moreTesting() called\n"</span>;   }}<span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">Results in Fatal error: Cannot override final method BaseClass::moreTesting()</span>

final 类, 表示此类不能被继续被 extends

<span style="color: #b0c4de;"><?php</span><span style="color: #00ffff;">final</span> <span style="color: #00ffff;">class</span> <span style="color: #98fb98;">BaseClass</span> {   <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">test</span>() {       <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">"BaseClass::test() called\n"</span>;   }   <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">这里无论你是否将方法声明为 final，都没有关系</span>   <span style="color: #00ffff;">final</span> <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">moreTesting</span>() {       <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">"BaseClass::moreTesting() called\n"</span>;   }}<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">ChildClass</span> <span style="color: #00ffff;">extends</span> <span style="color: #98fb98;">BaseClass</span> {}<span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">产生 Fatal error: Class ChildClass may not inherit from final class (BaseClass)</span>

const

<span style="color: #00ffff;">class</span>  <span style="color: #98fb98;">MyClass</span> {    <span style="color: #00ffff;">const</span>  <span style="color: #98fb98;">constant</span>  =  <span style="color: #ffa07a;">'constant value'</span> ;    <span style="color: #00ffff;">function</span>  <span style="color: #87cefa;">showConstant</span> () {        <span style="color: #00ffff;">echo</span>   <span style="color: #00ffff;">self</span> :: constant  .  <span style="color: #ffa07a;">"\n"</span> ;    }}<span style="color: #00ffff;">echo</span>  <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">class</span> :: constant . <span style="color: #ffa07a;">"\n"</span> ;  <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">自 PHP 5.3.0 起</span>

后期绑定, 又叫延迟绑定

延迟绑定的意思, self 的绑定是运行时候计算, 看下面

<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">Par</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">static</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">whoami</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'parent'</span>, <span style="color: #ffa07a;">'<br>'</span>;    }    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">static</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">say</span>() {        <span style="color: #00ffff;">self</span>::whoami();    }    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">static</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">say2</span>() {        <span style="color: #00ffff;">static</span>::whoami();    }}<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">Sun</span> <span style="color: #00ffff;">extends</span> <span style="color: #98fb98;">Par</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">static</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">whoami</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'sun'</span>, <span style="color: #ffa07a;">'<br>'</span>;    }}<span style="color: #7fffd4;">Sun</span>::say();                     <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">parent, 因为执行环境变成了 parent</span><span style="color: #7fffd4;">Sun</span>::say2();                    <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">sun, 保持静态</span>

单例模式 instanceof

<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">mysql</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">static</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">ins</span>;    <span style="color: #00ffff;">private</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">__construct</span>() {        <span style="color: #ff7f24;">/* </span><span style="color: #ff7f24;">do something */</span>    }    <span style="color: #00ffff;">private</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">__clone</span> () {}      <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">禁止继承的类修改自身, 也可以使用 final</span>    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">static</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">getIns</span>() {        <span style="color: #00ffff;">if</span> (!(<span style="color: #00ffff;">self</span>::<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">ins</span> <span style="color: #00ffff;">instanceof</span> <span style="color: #98fb98;">mysql</span>)) {            <span style="color: #00ffff;">self</span>::<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">ins</span> = <span style="color: #00ffff;">new</span> <span style="color: #00ffff;">self</span>();        }        <span style="color: #00ffff;">return</span> <span style="color: #00ffff;">self</span>::<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">ins</span>;    }}<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">a</span> = <span style="color: #7fffd4;">mysql</span>::getIns();<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">b</span> = <span style="color: #7fffd4;">mysql</span>::getIns();var_dump (<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">a</span> === <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">b</span>);              <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">true</span>

魔术方法

__get

<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">test</span> {    <span style="color: #00ffff;">public</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">hello</span> = <span style="color: #ffa07a;">'normal hello'</span>;    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">__get</span>(<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">args</span>) {        <span style="color: #00ffff;">if</span> (<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">args</span> == <span style="color: #ffa07a;">'hello'</span>) {            <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'from get: hello'</span>;        } <span style="color: #00ffff;">else</span> <span style="color: #00ffff;">if</span> (<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">args</span> = <span style="color: #ffa07a;">'other'</span>) {            <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'from get: other'</span>;        }    }}<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">test</span>();<span style="color: #00ffff;">echo</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t</span>-><span style="color: #eedd82;">hello</span>, <span style="color: #ffa07a;">'<br>'</span>;       <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">normal hello, 如果存在不会调用 魔术方法</span><span style="color: #00ffff;">echo</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t</span>-><span style="color: #eedd82;">other</span>;               <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">不能调用, 调用魔术方法</span>

__set

<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">test</span> {    <span style="color: #00ffff;">public</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">hello</span> = <span style="color: #ffa07a;">'normal hello'</span>;    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">__set</span>(<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">k</span>, <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">v</span>) {        <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'you want to set me! '</span>, <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">k</span>, <span style="color: #ffa07a;">'<br>'</span>;        <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #7fffd4;">this</span>-><span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">k</span> = <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">v</span>;    }}<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">test</span>();<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t</span>-><span style="color: #eedd82;">ttt</span> = 222;<span style="color: #00ffff;">echo</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t</span>-><span style="color: #eedd82;">ttt</span>;          <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">可以设置</span><span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t</span>-><span style="color: #eedd82;">hello</span> = <span style="color: #ffa07a;">'another hello'</span>;print_r(<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t</span>);<span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">you want to set me! ttt</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">222</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">test Object</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">(</span><span style="color: #ff7f24;">//   </span><span style="color: #ff7f24;">[hello] => another hello</span><span style="color: #ff7f24;">//   </span><span style="color: #ff7f24;">[ttt] => 222</span><span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">)</span>

__isset

class test {    public function __isset($v) {        return false;        .....        return true;    }}

$t = new test();if (isset($t->value)) {    echo 'isset';} else {    echo 'noset';}

__unset
调用的属性不存在, 就会调用此函数, 主要用于友好操作

__call
无权调用的时候, 传递两个参数, (function_NAME, array function_ARGS)

<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">test</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">func_empty</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'nothing here'</span>;    }    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">__call</span> (<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">func</span>, <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">args</span>) {        <span style="color: #00ffff;">self</span>::func_empty();    }}<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">test</span>();

<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">test</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">func_empty</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'nothing here'</span>;    }    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">__call</span> (<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">func</span>, <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">args</span>) {        print_r(<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">args</span>);        <span style="color: #00ffff;">self</span>::func_empty();    }}<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">test</span>();<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t</span>-><span style="color: #ffffff; background-color: #000000;">abc</span>(<span style="color: #ffa07a;">'abc'</span>, <span style="color: #ffa07a;">'def'</span>);<span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">Array ( [0] => abc [1] => def )</span>

__callStatic

public static function  __callStatic ( $name ,  $arguments ) { ... }

重载覆盖

覆盖: override 指的是子类覆盖父类的方法, 在 PHP 中, 如果 子类和父类的参数不一样会有警告
重载: redeclare 指的是同一个类中包含两个相同名字的方法, PHP 不支持

实现重载的方法

func_num_args()           返回数据的参数的个数$arr = func_get_args()    让参数以数组的形式返回func_get_arg(0)           返回第一个参数func_get_arg(1)           返回第二个参数

<span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">f</span>() {    <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">arr</span> = func_get_args();    <span style="color: #00ffff;">foreach</span>(<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">arr</span> <span style="color: #00ffff;">as</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">v</span>) {        ....   }}

魔术常量

__LINE____FILE____DIR____FUNCTION____CLASS____METHOD__

抽象类和接口

abstract

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abstract class Car {   abstract function func1();}class Fastcar extends Car {   public function func1() {     ...   }}

继承类必须实现抽象类的所有方法
抽象类可以有自己的属性
抽象类可以有自己的实现方法, 也叫具体方法, interface 没有
可以有 protected 方法, interface 不可以

interface

<span style="color: #00ffff;">interface</span> <span style="color: #98fb98;">iUsb</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">f</span>();}<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">phone</span> <span style="color: #00ffff;">implements</span> <span style="color: #98fb98;">iUsb</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">f</span>() {        ..    }}

定义规范

当多个类, 之间平级的, 有相同的方法, 但是实现不同

类可以实现多个接口, 接口可以实现多个接口

class t1 implements i1, i2, i3 { }interface i1 extends i2, i2, i3 {}

继承类要实现接口的全部方法
interface 不能有 private 的方法
interface 里面的属性只能是常量
interface 里面不能实现方法, 抽象类可以, (可以理解接口里面全都是抽象方法)
interface 可以定义常量

<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">Monkey</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">climb</span>() { ... }}<span style="color: #00ffff;">interface</span> <span style="color: #98fb98;">iBirdable</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">fly</span>();}<span style="color: #00ffff;">interface</span> <span style="color: #98fb98;">iFishable</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">swim</span>();}<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">NewMonkey</span> <span style="color: #00ffff;">extends</span> <span style="color: #98fb98;">Monkey</span> <span style="color: #00ffff;">implements</span> <span style="color: #98fb98;">iBirdable</span>, <span style="color: #98fb98;">iFishable</span> {    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">fly</span>()  { ... }    <span style="color: #00ffff;">public</span> <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">swim</span>() { ... }}

抽象类和接口的区别我不是 很熟悉 T_T, mark 个 todo 以后再来补充

如果要创建一个模型, 这个模型将由一些紧密的对象采用, 就可以使用抽象类. 如果要创建由一些不相关对象采用的功能, 使用接口
如果必须从多个来源继承行为, 就使用接口. 接口可以实现多个, 不可以继承多个抽象类
如果所有的类会有共享一个公共的行为实现, 就使用抽象类, 并在其中的实现该行为, 在接口中无法实现具体方法

命名空间

如果文件 1 有 test 对象, 文件 2 也有 test 对象
在文件 3

require 'file1.php';require 'file2.php';

那么就会出现冲突

test1.php

<span style="color: #b0c4de;"><?php</span><span style="color: #00ffff;">namespace</span> <span style="color: #98fb98;">test\file1</span>;<span style="color: #00ffff;">class</span> <span style="color: #98fb98;">test</span> {    <span style="color: #00ffff;">public</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">val</span> = <span style="color: #ffa07a;">'this is file 1'</span>;}

test2.php

<span style="color: #b0c4de;"><?php</span><span style="color: #00ffff;">namespace</span> <span style="color: #98fb98;">test\file2</span>;      <span style="color: #ff7f24;"># 也可以使用别的命名空间 ...\...\...\...</span><span style="color: #00ffff;">class</span> <span style="color: #98fb98;">test</span> {    <span style="color: #00ffff;">public</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">val</span> = <span style="color: #ffa07a;">'this is file 2'</span>;}

test.php 用于加载访问

<span style="color: #b0c4de;"><?php</span><span style="color: #00ffff;">require</span> <span style="color: #ffa07a;">'test1.php'</span>;<span style="color: #00ffff;">require</span> <span style="color: #ffa07a;">'test2.php'</span>;<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t1</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">test\file1\test</span>();<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t2</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">test\file2\test</span>();<span style="color: #00ffff;">echo</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t1</span>-><span style="color: #eedd82;">val</span>, <span style="color: #ffa07a;">'<br>'</span>;        <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">this is file1</span><span style="color: #00ffff;">echo</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t2</span>-><span style="color: #eedd82;">val</span>, <span style="color: #ffa07a;">'<br>'</span>;        <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">this is file2</span><span style="color: #00ffff;">use</span> <span style="color: #98fb98;">test\file1</span> <span style="color: #00ffff;">as</span> <span style="color: #98fb98;">file1</span>;<span style="color: #00ffff;">use</span> <span style="color: #98fb98;">test\file2</span> <span style="color: #00ffff;">as</span> <span style="color: #98fb98;">file2</span>;<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t3</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">file1\test</span>();<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t4</span> = <span style="color: #00ffff;">new</span> <span style="color: #98fb98;">file2\test</span>();<span style="color: #00ffff;">echo</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t3</span>-><span style="color: #eedd82;">val</span>, <span style="color: #ffa07a;">'<br>'</span>;        <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">this is file1</span><span style="color: #00ffff;">echo</span> <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">t4</span>-><span style="color: #eedd82;">val</span>, <span style="color: #ffa07a;">'<br>'</span>;        <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">this is file2</span>

其他对象方法

class_alias(class_name, new_classname)get_class (OBJ)$arr = get_declared_classes()       # 返回已经定义了的类get_parent_class (OBJ)interface_exists (INTER)            # 是否存在接口method_exists (OBJ, FUNC_NAME)      # 是否存在某个方法

自动加载

<span style="color: #00ffff;">function</span>  <span style="color: #87cefa;">__autoload</span> ( <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">class_name</span> ) {    <span style="color: #00ffff;">require</span>  <span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">class_name</span>  .  <span style="color: #ffa07a;">'.php'</span> ;}<span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">obj</span>   = <span style="color: #00ffff;">new</span>  <span style="color: #98fb98;">MyClass1</span> ();      <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">自动会调用上面的哪个函数, 参数名是 MyClass1</span><span style="color: #ffffff; background-color: #000000;">$</span><span style="color: #eedd82;">obj2</span>  = <span style="color: #00ffff;">new</span>  <span style="color: #98fb98;">MyClass2</span> ();      <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">自动会调用上面的哪个函数, 参数名是 MyClass2</span>

为什么函数里面的 require class 的生活周期可以到外层, 原因像下面的,
__autoload 被执行之后, 就相当于把函数里面的代码展示出来

<span style="color: #00ffff;">function</span> <span style="color: #87cefa;">well</span>() {    <span style="color: #00ffff;">function</span> <span style="color: #87cefa;">test</span>() {        <span style="color: #00ffff;">echo</span> <span style="color: #ffa07a;">'inside '</span>, <span style="color: #ffa07a;">'<br>'</span>;    }}well();      <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">一定要先调用</span>test();      <span style="color: #ff7f24;">// </span><span style="color: #ff7f24;">inside</span>

__autoload 的实现spl_autoload_register —— 注册给定的函数作为 __autoload 的实现

<span style="color: #00ffff;">function</span> <span style="color: #87cefa;">func</span>() {    <span style="color: #00ffff;">require</span> <span style="color: #ffa07a;">'...'</span>;}spl_autoload_register(func);