uTools-Manuals/docs/php/apcu_exists.html
2019-04-28 19:00:34 +08:00

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<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Checks if entry exists</title>
</head>
<body class="docs"><div id="layout">
<div id="layout-content"><div id="function.apcu-exists" class="refentry">
<div class="refnamediv">
<h1 class="refname">apcu_exists</h1>
<p class="verinfo">(PECL apcu &gt;= 4.0.0)</p><p class="refpurpose"><span class="refname">apcu_exists</span> &mdash; <span class="dc-title">Checks if entry exists</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.apcu-exists-description">
<h3 class="title">说明</h3>
<div class="methodsynopsis dc-description">
<span class="methodname"><strong>apcu_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">$keys</code></span>
) : <span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span></div>
<p class="para rdfs-comment">
Checks if one or more APCu entries exist.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.apcu-exists-parameters">
<h3 class="title">参数</h3>
<dl>
<dt>
<code class="parameter">keys</code></dt>
<dd>
<p class="para">
A <span class="type"><a href="language.types.string.html" class="type string">string</a></span>, or an <span class="type"><a href="language.types.array.html" class="type array">array</a></span> of strings, that
contain keys.
</p>
</dd>
</dl>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.apcu-exists-returnvalues">
<h3 class="title">返回值</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> if the key exists, otherwise <strong><code>FALSE</code></strong> Or if an
<span class="type"><a href="language.types.array.html" class="type array">array</a></span> was passed to <code class="parameter">keys</code>, then
an array is returned that contains all existing keys, or an empty
array if none exist.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.apcu-exists-examples">
<h3 class="title">范例</h3>
<div class="example" id="example-420">
<p><strong>Example #1 <span class="function"><strong>apcu_exists()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />$fruit&nbsp;&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">'apple'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$veggie&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">'carrot'</span><span style="color: #007700">;<br /><br /></span><span style="color: #0000BB">apcu_store</span><span style="color: #007700">(</span><span style="color: #DD0000">'foo'</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$fruit</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">apcu_store</span><span style="color: #007700">(</span><span style="color: #DD0000">'bar'</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$veggie</span><span style="color: #007700">);<br /><br />if&nbsp;(</span><span style="color: #0000BB">apcu_exists</span><span style="color: #007700">(</span><span style="color: #DD0000">'foo'</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"Foo&nbsp;exists:&nbsp;"</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #0000BB">apcu_fetch</span><span style="color: #007700">(</span><span style="color: #DD0000">'foo'</span><span style="color: #007700">);<br />}&nbsp;else&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"Foo&nbsp;does&nbsp;not&nbsp;exist"</span><span style="color: #007700">;<br />}<br /><br />echo&nbsp;</span><span style="color: #0000BB">PHP_EOL</span><span style="color: #007700">;<br />if&nbsp;(</span><span style="color: #0000BB">apcu_exists</span><span style="color: #007700">(</span><span style="color: #DD0000">'baz'</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"Baz&nbsp;exists."</span><span style="color: #007700">;<br />}&nbsp;else&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"Baz&nbsp;does&nbsp;not&nbsp;exist"</span><span style="color: #007700">;<br />}<br /><br />echo&nbsp;</span><span style="color: #0000BB">PHP_EOL</span><span style="color: #007700">;<br /><br /></span><span style="color: #0000BB">$ret&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">apcu_exists</span><span style="color: #007700">(array(</span><span style="color: #DD0000">'foo'</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">'donotexist'</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">'bar'</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$ret</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
</div>
<div class="example-contents"><p>以上例程的输出类似于:</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
Foo exists: apple
Baz does not exist
array(2) {
[&quot;foo&quot;]=&gt;
bool(true)
[&quot;bar&quot;]=&gt;
bool(true)
}
</pre></div>
</div>
</div>
</div>
<div class="refsect1 seealso" id="refsect1-function.apcu-exists-seealso">
<h3 class="title">参见</h3>
<ul class="simplelist">
<li class="member"><span class="function"><a href="apcu_cache_info.html" class="function" rel="rdfs-seeAlso">apcu_cache_info()</a> - Retrieves cached information from APCu's data store</span></li>
<li class="member"><span class="function"><a href="apcu_fetch.html" class="function" rel="rdfs-seeAlso">apcu_fetch()</a> - Fetch a stored variable from the cache</span></li>
</ul>
</div>
</div></div></div></body></html>