public、protected、private的区别
通过className::functionNmae()、实例化、parent、self得出结论
className::functionNmae() 需是静态方法(public模式)
parent::functionNmae() 父类需是静态方法(public、protected两种模式)
self::functionNmae() 该类需是静态方法(三种模式)
实例化:实例化后可访问public模式的静态方法或普通方法
一、直接访问(通过 className::functionNmae()和实例化):
结论:
| 可以 通过 className::functionNmae() 访问
public
| 可以 通过实例 $obj->functionName() 访问
| 不可 通过 className::functionNmae() 访问
protected
| 不可 通过实例 $obj->functionName() 访问
| 不可 通过 className::functionNmae() 访问
private
| 不可 通过实例 $obj->functionName() 访问
<span style="color: #000000;">php</span><span style="color: #008000;">/*</span><span style="color: #008000;">* * * @authors HG ([email protected]) * @date 2015-05-26 17:12:02 * @version 1.0 </span><span style="color: #008000;">*/</span><span style="color: #008080;">header</span>("Content-type:text/html;charset=utf-8"<span style="color: #000000;">);</span><span style="color: #0000ff;">class</span><span style="color: #000000;"> A { </span><span style="color: #0000ff;">static</span> <span style="color: #800080;">$name</span>='这是类A的静态变量'<span style="color: #000000;">; </span><span style="color: #0000ff;">static</span> <span style="color: #0000ff;">public</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> stc_pc(){ </span><span style="color: #0000ff;">echo</span> '这是类A的公共静态方法<br>'<span style="color: #000000;">; } </span><span style="color: #0000ff;">static</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> stc(){ </span><span style="color: #0000ff;">echo</span> '这是类A的静态方法<br>'<span style="color: #000000;">; } </span><span style="color: #0000ff;">static</span> <span style="color: #0000ff;">protected</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> stc_pd(){ </span><span style="color: #0000ff;">echo</span> '这是类A受保护的静态方法<br>'<span style="color: #000000;">; } </span><span style="color: #0000ff;">static</span> <span style="color: #0000ff;">private</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> stc_pe(){ </span><span style="color: #0000ff;">echo</span> '这是类A私有的静态方法<br>'<span style="color: #000000;">; }}A</span>::stc_pc();<span style="color: #008000;">//</span><span style="color: #008000;">可访问</span><span style="color: #000000;">A</span>::stc();<span style="color: #008000;">//</span><span style="color: #008000;">可访问</span><span style="color: #000000;">A</span>::<span style="color: #800080;">$name</span>;<span style="color: #008000;">//</span><span style="color: #008000;">不报错//A::stc_pd();//不可访问//A::stc_pe();//不可访问</span><span style="color: #0000ff;">echo</span> '<br><br>通过实例化访问<br><br>'<span style="color: #000000;">;</span><span style="color: #800080;">$a</span> = <span style="color: #0000ff;">new</span><span style="color: #000000;"> A();</span><span style="color: #800080;">$a</span>->stc_pc();<span style="color: #008000;">//</span><span style="color: #008000;">可访问</span><span style="color: #800080;">$a</span>->stc();<span style="color: #008000;">//</span><span style="color: #008000;">可访问//$a->$name;//报错//$a->stc_pd();//不可访问//$a->stc_pe();//不可访问</span><span style="color: #008000;">/*</span><span style="color: #008000;">******************* | 可以 通过 className::functionNmae() 访问public | | 可以 通过实例 $obj->functionName() 访问 | 不可 通过 className::functionNmae() 访问protected | | 不可 通过实例 $obj->functionName() 访问 | 不可 通过 className::functionNmae() 访问private | | 不可 通过实例 $obj->functionName() 访问 *******************</span><span style="color: #008000;">*/</span>
二、直接访问(self::functionNmae())
结论:
self::functionNmae();需是静态方法(三种模式都可)
<span style="color: #000000;">php</span><span style="color: #008000;">/*</span><span style="color: #008000;">* * * @authors HG ([email protected]) * @date 2015-05-26 17:18:50 * @version 1.0 </span><span style="color: #008000;">*/</span><span style="color: #008080;">header</span>("Content-type:text/html;charset=utf-8"<span style="color: #000000;">);</span><span style="color: #0000ff;">class</span><span style="color: #000000;"> C { </span><span style="color: #0000ff;">static</span> <span style="color: #800080;">$name</span> = "静态变量"<span style="color: #000000;">; </span><span style="color: #0000ff;">static</span> <span style="color: #0000ff;">public</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> stc_pc(){ </span><span style="color: #0000ff;">echo</span> '静态公共方法<br>'<span style="color: #000000;">; self</span>::<span style="color: #000000;">stc_pd(); self</span>::<span style="color: #000000;">stc_pe(); self</span>::<span style="color: #000000;">stc(); </span><span style="color: #008000;">//</span><span style="color: #008000;">self::func();//报错但有结果</span><span style="color: #000000;"> } </span><span style="color: #0000ff;">static</span> <span style="color: #0000ff;">protected</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> stc_pd(){ </span><span style="color: #0000ff;">echo</span> '静态受保护方法<br>'<span style="color: #000000;">; } </span><span style="color: #0000ff;">static</span> <span style="color: #0000ff;">private</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> stc_pe(){ </span><span style="color: #0000ff;">echo</span> '静态受保护方法<br>'<span style="color: #000000;">; } </span><span style="color: #0000ff;">static</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> stc(){ </span><span style="color: #0000ff;">echo</span> '静态普通方法<br>'<span style="color: #000000;">; } </span><span style="color: #0000ff;">function</span><span style="color: #000000;"> func(){ </span><span style="color: #0000ff;">echo</span> '普通方法<br>'<span style="color: #000000;">; } }C</span>::<span style="color: #000000;">stc_pc();</span><span style="color: #008000;">/*</span><span style="color: #008000;">*****self::functionNmae();需是静态方法(三种模式都可)*****</span><span style="color: #008000;">*/</span>
三、通过子类访问父类(parent::functionNmae()和实例化)
结论:
parent::functionNmae(); private不可访问
$obj->functionNmae(); private不可访问
<span style="color: #000000;">php</span><span style="color: #008000;">/*</span><span style="color: #008000;">* * * @authors HG ([email protected]) * @date 2015-05-26 17:18:50 * @version 1.0 </span><span style="color: #008000;">*/</span><span style="color: #008080;">header</span>("Content-type:text/html;charset=utf-8"<span style="color: #000000;">);</span><span style="color: #0000ff;">include</span> '/class_a.php'<span style="color: #000000;">;</span><span style="color: #0000ff;">class</span> B <span style="color: #0000ff;">extends</span><span style="color: #000000;"> A{ </span><span style="color: #0000ff;">static</span> <span style="color: #0000ff;">public</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> index(){ parent</span>::<span style="color: #000000;">stc_pc(); parent</span>::<span style="color: #000000;">stc(); parent</span>::<span style="color: #000000;">stc_pd(); parent</span>::<span style="color: #800080;">$name</span>;<span style="color: #008000;">//</span><span style="color: #008000;">不报错 //parent::stc_pe();//不可访问</span> <span style="color: #0000ff;">echo</span> '<br><br>通过实例化访问<br><br>'<span style="color: #000000;">; </span><span style="color: #800080;">$a</span> = <span style="color: #0000ff;">new</span><span style="color: #000000;"> A(); </span><span style="color: #800080;">$a</span>-><span style="color: #000000;">stc_pc(); </span><span style="color: #800080;">$a</span>-><span style="color: #000000;">stc(); </span><span style="color: #800080;">$a</span>-><span style="color: #000000;">stc_pd(); </span><span style="color: #800080;">$a</span>-><span style="color: #800080;">$name</span>;<span style="color: #008000;">//</span><span style="color: #008000;">报错 //$a->stc_pe();//不可</span><span style="color: #000000;"> } }B</span>::<span style="color: #000000;">index();</span><span style="color: #008000;">/*</span><span style="color: #008000;">*****在子类中通过:parent::functionNmae(); private不可访问$obj->functionNmae(); private不可访问*****</span><span style="color: #008000;">*/</span>
四、
<span style="color: #000000;">php</span><span style="color: #008000;">/*</span><span style="color: #008000;">* * * @authors HG ([email protected]) * @date 2015-05-28 11:54:03 * @version 1.0 </span><span style="color: #008000;">*/</span><span style="color: #0000ff;">class</span><span style="color: #000000;"> functioninc{ </span><span style="color: #0000ff;">function</span><span style="color: #000000;"> fc_a(){ </span><span style="color: #0000ff;">echo</span> '000 '<span style="color: #000000;">; } </span><span style="color: #0000ff;">static</span> <span style="color: #0000ff;">protected</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> fc_b(){ </span><span style="color: #0000ff;">echo</span> '111 '<span style="color: #000000;">; } }</span><span style="color: #0000ff;">class</span> fun <span style="color: #0000ff;">extends</span><span style="color: #000000;"> functioninc { </span><span style="color: #0000ff;">static</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> a(){ parent</span>::fc_a(); <span style="color: #008000;">//</span><span style="color: #008000;">报错 fc_a()不是静态方法</span> parent::<span style="color: #000000;">fc_b(); } </span><span style="color: #0000ff;">function</span><span style="color: #000000;"> b(){ parent</span>::<span style="color: #000000;">fc_a(); parent</span>::<span style="color: #000000;">fc_b(); }}</span><span style="color: #008000;">/*</span><span style="color: #008000;">在子类中静态方法通过parent调用父类方法,父类方法需是静态方法。普通方法通过parent调用父类方法,不限制。</span><span style="color: #008000;">*/</span><span style="color: #800080;">$a</span> = <span style="color: #0000ff;">new</span><span style="color: #000000;"> fun();</span><span style="color: #800080;">$a</span>-><span style="color: #000000;">a();</span><span style="color: #800080;">$a</span>->b();