PageRenderTime 43ms CodeModel.GetById 13ms RepoModel.GetById 0ms app.codeStats 0ms

/php/language.oop5.interfaces.html

https://bitbucket.org/thncr/manuals
HTML | 100 lines | 94 code | 6 blank | 0 comment | 0 complexity | f863a8433cded135f25227a753fd59fc MD5 | raw file
    

  1. <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    2. 

  2. <html>
    3. 

  3.  <head>
    4. 

  4.   <meta http-equiv="content-type" content="text/html; charset=UTF-8">
    5. 

  5.   <title>接口</title>
    6. 

  6. 

  7.  </head>
    8. 

  8.  <body><div class="manualnavbar" style="text-align: center;">
    9. 

  9.  <div class="prev" style="text-align: left; float: left;"><a href="language.oop5.abstract.html">抽象类</a></div>
    10. 

  10.  <div class="next" style="text-align: right; float: right;"><a href="language.oop5.traits.html">Traits</a></div>
    11. 

  11.  <div class="up"><a href="language.oop5.html">类与对象</a></div>
    12. 

  12.  <div class="home"><a href="index.html">PHP Manual</a></div>
    13. 

  13. </div><hr /><div id="language.oop5.interfaces" class="sect1">
    14. 

  14.   <h2 class="title">接口</h2>
    15. 

  15.   <p class="para">
    16. 

  16.   使用接口（interface），你可以指定某个类必须实现哪些方法，但不需要定义这些方法的具体内容。
    17. 

  17.   </p>
    18. 

  18.   <p class="para">
    19. 

  19.     我们可以通过interface来定义一个接口，就像定义一个标准的类一样，但其中定义所有的方法都是空的。
    20. 

  20.   </p>
    21. 

  21.   <p class="para">
    22. 

  22.   接口中定义的所有方法都必须是public，这是接口的特性。
    23. 

  23.   </p>
    24. 

  24.   <div class="sect2" id="language.oop5.interfaces.implements">
    25. 

  25.    <h3 class="title"><em>实现</em></h3>
    26. 

  26.    <p class="para">   
    27. 

  27.     要实现一个接口，可以使用<em>implements</em>操作符。类中必须实现接口中定义的所有方法，否则
    28. 

  28.     会报一个fatal错误。如果要实现多个接口，可以用逗号来分隔多个接口的名称。
    29. 

  29.    </p>
    30. 

  30.    <blockquote class="note"><p><strong class="note">Note</strong>: 
    31. 

  31.     <p class="para">
    32. 

  32.      实现多个接口时，接口中的方法不能有重名。
    33. 

  33.     </p>
    34. 

  34.    </p></blockquote>
    35. 

  35.    <blockquote class="note"><p><strong class="note">Note</strong>: 
    36. 

  36.     <p class="para">
    37. 

  37.      接口也可以继承，通过使用<em>extends</em>操作符。
    38. 

  38.     </p>
    39. 

  39.    </p></blockquote>
    40. 

  40.   </div>
    41. 

  41.   <div class="sect2" id="language.oop5.interfaces.constants">
    42. 

  42.    <h3 class="title"><em>常量</em></h3>
    43. 

  43.    <p class="para"> 
    44. 

  44.     接口中也可以定义常量。接口常量和<a href="language.oop5.constants.html" class="link">类常量</a>的使用完全相同。
    45. 

  45.     它们都是定值，不能被子类或子接口修改。
    46. 

  46.    </p>
    47. 

  47.   </div>
    48. 

  48.   <div class="sect2" id="language.oop5.interfaces.examples">
    49. 

  49.    <h3 class="title">范例</h3>
    50. 

  50.    <div class="example" id="language.oop5.interfaces.examples.ex1">
    51. 

  51.     <p><strong>Example #1 接口代码示例</strong></p>
    52. 

  52.      <div class="example-contents">
    53. 

  53. <div class="phpcode"><code><span style="color: #000000">
    54. 

  54. <span style="color: #0000BB">&lt;?php<br /><br /></span><span style="color: #FF8000">//&nbsp;声明一个'iTemplate'接口<br /></span><span style="color: #007700">interface&nbsp;</span><span style="color: #0000BB">iTemplate<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">setVariable</span><span style="color: #007700">(</span><span style="color: #0000BB">$name</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$var</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">getHtml</span><span style="color: #007700">(</span><span style="color: #0000BB">$template</span><span style="color: #007700">);<br />}<br /><br /><br /></span><span style="color: #FF8000">//&nbsp;实现接口<br />//&nbsp;下面的写法是正确的<br /></span><span style="color: #007700">class&nbsp;</span><span style="color: #0000BB">Template&nbsp;</span><span style="color: #007700">implements&nbsp;</span><span style="color: #0000BB">iTemplate<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;private&nbsp;</span><span style="color: #0000BB">$vars&nbsp;</span><span style="color: #007700">=&nbsp;array();<br />&nbsp;&nbsp;<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">setVariable</span><span style="color: #007700">(</span><span style="color: #0000BB">$name</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$var</span><span style="color: #007700">)<br />&nbsp;&nbsp;&nbsp;&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$this</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">vars</span><span style="color: #007700">[</span><span style="color: #0000BB">$name</span><span style="color: #007700">]&nbsp;=&nbsp;</span><span style="color: #0000BB">$var</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />&nbsp;&nbsp;<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">getHtml</span><span style="color: #007700">(</span><span style="color: #0000BB">$template</span><span style="color: #007700">)<br />&nbsp;&nbsp;&nbsp;&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;foreach(</span><span style="color: #0000BB">$this</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">vars&nbsp;</span><span style="color: #007700">as&nbsp;</span><span style="color: #0000BB">$name&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">$value</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$template&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">str_replace</span><span style="color: #007700">(</span><span style="color: #DD0000">'{'&nbsp;</span><span style="color: #007700">.&nbsp;</span><span style="color: #0000BB">$name&nbsp;</span><span style="color: #007700">.&nbsp;</span><span style="color: #DD0000">'}'</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$value</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$template</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br />&nbsp;<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;</span><span style="color: #0000BB">$template</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />}<br /><br /></span><span style="color: #FF8000">//&nbsp;下面的写法是错误的，会报错：<br />//&nbsp;Fatal&nbsp;error:&nbsp;Class&nbsp;BadTemplate&nbsp;contains&nbsp;1&nbsp;abstract&nbsp;methods<br />//&nbsp;and&nbsp;must&nbsp;therefore&nbsp;be&nbsp;declared&nbsp;abstract&nbsp;(iTemplate::getHtml)<br /></span><span style="color: #007700">class&nbsp;</span><span style="color: #0000BB">BadTemplate&nbsp;</span><span style="color: #007700">implements&nbsp;</span><span style="color: #0000BB">iTemplate<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;private&nbsp;</span><span style="color: #0000BB">$vars&nbsp;</span><span style="color: #007700">=&nbsp;array();<br />&nbsp;&nbsp;<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">setVariable</span><span style="color: #007700">(</span><span style="color: #0000BB">$name</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$var</span><span style="color: #007700">)<br />&nbsp;&nbsp;&nbsp;&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$this</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">vars</span><span style="color: #007700">[</span><span style="color: #0000BB">$name</span><span style="color: #007700">]&nbsp;=&nbsp;</span><span style="color: #0000BB">$var</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />}<br /></span><span style="color: #0000BB">?&gt;</span>
    55. 

  55. </span>
    56. 

  56. </code></div>
    57. 

  57.     </div>
    58. 

  58. 

  59.    </div>
    60. 

  60.    <div class="example" id="language.oop5.interfaces.examples.ex2">
    61. 

  61.     <p><strong>Example #2 Extendable Interfaces</strong></p>
    62. 

  62.      <div class="example-contents">
    63. 

  63. <div class="phpcode"><code><span style="color: #000000">
    64. 

  64. <span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">interface&nbsp;</span><span style="color: #0000BB">a<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">foo</span><span style="color: #007700">();<br />}<br /><br />interface&nbsp;</span><span style="color: #0000BB">b&nbsp;</span><span style="color: #007700">extends&nbsp;</span><span style="color: #0000BB">a<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">baz</span><span style="color: #007700">(</span><span style="color: #0000BB">Baz&nbsp;$baz</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #FF8000">//&nbsp;正确写法<br /></span><span style="color: #007700">class&nbsp;</span><span style="color: #0000BB">c&nbsp;</span><span style="color: #007700">implements&nbsp;</span><span style="color: #0000BB">b<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">foo</span><span style="color: #007700">()<br />&nbsp;&nbsp;&nbsp;&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">baz</span><span style="color: #007700">(</span><span style="color: #0000BB">Baz&nbsp;$baz</span><span style="color: #007700">)<br />&nbsp;&nbsp;&nbsp;&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />}<br /><br /></span><span style="color: #FF8000">//&nbsp;错误写法会导致一个fatal&nbsp;error<br /></span><span style="color: #007700">class&nbsp;</span><span style="color: #0000BB">d&nbsp;</span><span style="color: #007700">implements&nbsp;</span><span style="color: #0000BB">b<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">foo</span><span style="color: #007700">()<br />&nbsp;&nbsp;&nbsp;&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">baz</span><span style="color: #007700">(</span><span style="color: #0000BB">Foo&nbsp;$foo</span><span style="color: #007700">)<br />&nbsp;&nbsp;&nbsp;&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />}<br /></span><span style="color: #0000BB">?&gt;</span>
    65. 

  65. </span>
    66. 

  66. </code></div>
    67. 

  67.      </div>
    68. 

  68. 

  69.    </div>
    70. 

  70.    <div class="example" id="language.oop5.interfaces.examples.ex3">
    71. 

  71.     <p><strong>Example #3 多个接口间的继承</strong></p>
    72. 

  72.      <div class="example-contents">
    73. 

  73. <div class="phpcode"><code><span style="color: #000000">
    74. 

  74. <span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">interface&nbsp;</span><span style="color: #0000BB">a<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">foo</span><span style="color: #007700">();<br />}<br /><br />interface&nbsp;</span><span style="color: #0000BB">b<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">bar</span><span style="color: #007700">();<br />}<br /><br />interface&nbsp;</span><span style="color: #0000BB">c&nbsp;</span><span style="color: #007700">extends&nbsp;</span><span style="color: #0000BB">a</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">b<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">baz</span><span style="color: #007700">();<br />}<br /><br />class&nbsp;</span><span style="color: #0000BB">d&nbsp;</span><span style="color: #007700">implements&nbsp;</span><span style="color: #0000BB">c<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">foo</span><span style="color: #007700">()<br />&nbsp;&nbsp;&nbsp;&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">bar</span><span style="color: #007700">()<br />&nbsp;&nbsp;&nbsp;&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">baz</span><span style="color: #007700">()<br />&nbsp;&nbsp;&nbsp;&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />}<br /></span><span style="color: #0000BB">?&gt;</span>
    75. 

  75. </span>
    76. 

  76. </code></div>
    77. 

  77.      </div>
    78. 

  78. 

  79.    </div>
    80. 

  80.    <div class="example" id="language.oop5.interfaces.examples.ex4">
    81. 

  81.     <p><strong>Example #4 使用接口常量</strong></p>
    82. 

  82.      <div class="example-contents">
    83. 

  83. <div class="phpcode"><code><span style="color: #000000">
    84. 

  84. <span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">interface&nbsp;</span><span style="color: #0000BB">a<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;const&nbsp;</span><span style="color: #0000BB">b&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">'Interface&nbsp;constant'</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #FF8000">//&nbsp;输出接口常量<br /></span><span style="color: #007700">echo&nbsp;</span><span style="color: #0000BB">a</span><span style="color: #007700">::</span><span style="color: #0000BB">b</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">//&nbsp;错误写法，因为常量的值不能被修改。接口常量的概念和类常量是一样的。<br /></span><span style="color: #007700">class&nbsp;</span><span style="color: #0000BB">b&nbsp;</span><span style="color: #007700">implements&nbsp;</span><span style="color: #0000BB">a<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;const&nbsp;</span><span style="color: #0000BB">b&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">'Class&nbsp;constant'</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?&gt;</span>
    85. 

  85. </span>
    86. 

  86. </code></div>
    87. 

  87.      </div>
    88. 

  88. 

  89.    </div>
    90. 

  90.    <p class="simpara">
    91. 

  91.       你也可以看看<a href="language.operators.type.html" class="link">instanceof</a>关键字的文档。
    92. 

  92.    </p>
    93. 

  93.   </div>
    94. 

  94. 

  95.  </div><hr /><div class="manualnavbar" style="text-align: center;">
    96. 

  96.  <div class="prev" style="text-align: left; float: left;"><a href="language.oop5.abstract.html">抽象类</a></div>
    97. 

  97.  <div class="next" style="text-align: right; float: right;"><a href="language.oop5.traits.html">Traits</a></div>
    98. 

  98.  <div class="up"><a href="language.oop5.html">类与对象</a></div>
    99. 

  99.  <div class="home"><a href="index.html">PHP Manual</a></div>
    100. 

  100. </div></body></html>
    101. 

  101.