mirror of
https://github.com/fofolee/uTools-Manuals.git
synced 2025-06-18 05:26:57 +08:00
146 lines
8.3 KiB
HTML
146 lines
8.3 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<head>
|
|
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
|
|
<title>检查对象或类是否具有该属性</title>
|
|
</head>
|
|
<body class="docs"><div id="layout">
|
|
<div id="layout-content"><div id="function.property-exists" class="refentry">
|
|
<div class="refnamediv">
|
|
<h1 class="refname">property_exists</h1>
|
|
<p class="verinfo">(PHP 5 >= 5.1.0, PHP 7)</p><p class="refpurpose"><span class="refname">property_exists</span> — <span class="dc-title">检查对象或类是否具有该属性</span></p>
|
|
|
|
</div>
|
|
<div class="refsect1 description" id="refsect1-function.property-exists-description">
|
|
<h3 class="title">说明</h3>
|
|
<div class="methodsynopsis dc-description">
|
|
<span class="methodname"><strong>property_exists</strong></span>
|
|
( <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$class</code></span>
|
|
, <span class="methodparam"><span class="type">string</span> <code class="parameter">$property</code></span>
|
|
) : <span class="type">bool</span></div>
|
|
|
|
<p class="para rdfs-comment">
|
|
本函数检查给出的 <code class="parameter">property</code> 是否存在于指定的类中（以及是否能在当前范围内访问）。
|
|
</p>
|
|
<blockquote class="note"><p><strong class="note">Note</strong>:
|
|
<p class="para">
|
|
As opposed with <span class="function"><a href="isset.html" class="function">isset()</a></span>,
|
|
<span class="function"><strong>property_exists()</strong></span> returns <strong><code>TRUE</code></strong> even if the property
|
|
has the value <strong><code>NULL</code></strong>.
|
|
</p>
|
|
</p></blockquote>
|
|
</div>
|
|
|
|
|
|
<div class="refsect1 parameters" id="refsect1-function.property-exists-parameters">
|
|
<h3 class="title">参数</h3>
|
|
<p class="para">
|
|
<dl>
|
|
|
|
|
|
<dt>
|
|
<code class="parameter">class</code></dt>
|
|
|
|
<dd>
|
|
|
|
<p class="para">
|
|
字符串形式的类名或要检查的类的一个对象
|
|
</p>
|
|
</dd>
|
|
|
|
|
|
|
|
<dt>
|
|
<code class="parameter">property</code></dt>
|
|
|
|
<dd>
|
|
|
|
<p class="para">
|
|
属性的名字
|
|
</p>
|
|
</dd>
|
|
|
|
|
|
</dl>
|
|
|
|
</p>
|
|
</div>
|
|
|
|
|
|
<div class="refsect1 returnvalues" id="refsect1-function.property-exists-returnvalues">
|
|
<h3 class="title">返回值</h3>
|
|
<p class="para">
|
|
如果该属性存在则返回 <strong><code>TRUE</code></strong>，如果不存在则返回 <strong><code>FALSE</code></strong>，出错返回 <strong><code>NULL</code></strong>。
|
|
</p>
|
|
</div>
|
|
|
|
|
|
<div class="refsect1 notes" id="refsect1-function.property-exists-notes">
|
|
<h3 class="title">注释</h3>
|
|
<blockquote class="note"><p><strong class="note">Note</strong>: <p class="para">如果此类不是已知类，使用此函数会使用任何已注册的
|
|
<a href="language.oop5.autoload.html" class="link">autoloader</a>。</p></p></blockquote>
|
|
<blockquote class="note"><p><strong class="note">Note</strong>:
|
|
<p class="para">
|
|
The <span class="function"><strong>property_exists()</strong></span> function cannot detect properties
|
|
that are magically accessible using the <a href="language.oop5.overloading.html#language.oop5.overloading.members" class="link"><em>__get</em></a>
|
|
magic method.
|
|
</p>
|
|
</p></blockquote>
|
|
</div>
|
|
|
|
|
|
<div class="refsect1 changelog" id="refsect1-function.property-exists-changelog">
|
|
<h3 class="title">更新日志</h3>
|
|
<p class="para">
|
|
<table class="doctable informaltable">
|
|
|
|
<thead>
|
|
<tr>
|
|
<th>版本</th>
|
|
<th>说明</th>
|
|
</tr>
|
|
|
|
</thead>
|
|
|
|
<tbody class="tbody">
|
|
<tr>
|
|
<td>5.3.0</td>
|
|
<td>
|
|
This function checks the existence of a property independent of
|
|
accessibility.
|
|
</td>
|
|
</tr>
|
|
|
|
</tbody>
|
|
|
|
</table>
|
|
|
|
</p>
|
|
</div>
|
|
|
|
<div class="refsect1 examples" id="refsect1-function.property-exists-examples">
|
|
<h3 class="title">范例</h3>
|
|
<p class="para">
|
|
<div class="example" id="example-6153">
|
|
<p><strong>Example #1 A <span class="function"><strong>property_exists()</strong></span> example</strong></p>
|
|
<div class="example-contents">
|
|
<div class="phpcode"><pre><span style="color: #000000">
|
|
<span style="color: #0000BB"><?php<br /><br /></span><span style="color: #007700">class </span><span style="color: #0000BB">myClass </span><span style="color: #007700">{<br /> public </span><span style="color: #0000BB">$mine</span><span style="color: #007700">;<br /> private </span><span style="color: #0000BB">$xpto</span><span style="color: #007700">;<br /> static protected </span><span style="color: #0000BB">$test</span><span style="color: #007700">;<br /><br /> static function </span><span style="color: #0000BB">test</span><span style="color: #007700">() {<br /> </span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">property_exists</span><span style="color: #007700">(</span><span style="color: #DD0000">'myClass'</span><span style="color: #007700">, </span><span style="color: #DD0000">'xpto'</span><span style="color: #007700">)); </span><span style="color: #FF8000">//true<br /> </span><span style="color: #007700">}<br />}<br /><br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">property_exists</span><span style="color: #007700">(</span><span style="color: #DD0000">'myClass'</span><span style="color: #007700">, </span><span style="color: #DD0000">'mine'</span><span style="color: #007700">)); </span><span style="color: #FF8000">//true<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">property_exists</span><span style="color: #007700">(new </span><span style="color: #0000BB">myClass</span><span style="color: #007700">, </span><span style="color: #DD0000">'mine'</span><span style="color: #007700">)); </span><span style="color: #FF8000">//true<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">property_exists</span><span style="color: #007700">(</span><span style="color: #DD0000">'myClass'</span><span style="color: #007700">, </span><span style="color: #DD0000">'xpto'</span><span style="color: #007700">)); </span><span style="color: #FF8000">//true, as of PHP 5.3.0<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">property_exists</span><span style="color: #007700">(</span><span style="color: #DD0000">'myClass'</span><span style="color: #007700">, </span><span style="color: #DD0000">'bar'</span><span style="color: #007700">)); </span><span style="color: #FF8000">//false<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">property_exists</span><span style="color: #007700">(</span><span style="color: #DD0000">'myClass'</span><span style="color: #007700">, </span><span style="color: #DD0000">'test'</span><span style="color: #007700">)); </span><span style="color: #FF8000">//true, as of PHP 5.3.0<br /></span><span style="color: #0000BB">myClass</span><span style="color: #007700">::</span><span style="color: #0000BB">test</span><span style="color: #007700">();<br /><br /></span><span style="color: #0000BB">?></span>
|
|
</span>
|
|
</pre></div>
|
|
</div>
|
|
|
|
</div>
|
|
</p>
|
|
</div>
|
|
|
|
<div class="refsect1 seealso" id="refsect1-function.property-exists-seealso">
|
|
<h3 class="title">参见</h3>
|
|
<p class="para">
|
|
<ul class="simplelist">
|
|
<li class="member"><span class="function"><a href="method_exists.html" class="function" rel="rdfs-seeAlso">method_exists()</a> - 检查类的方法是否存在</span></li>
|
|
</ul>
|
|
</p>
|
|
</div>
|
|
|
|
</div></div></div></body></html> |