PHP – 面向对象
Table of Contents
- 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:
- 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
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 3require '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);TODO SPL 函数
- __set
- clone 会生成一个新的对象, 但不会调用构造函数