mirror of
https://github.com/fofolee/uTools-Manuals.git
synced 2025-06-18 13:57:03 +08:00
203 lines
12 KiB
HTML
203 lines
12 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>去除字符串首尾处的空白字符（或者其他字符）</title>
|
||
</head>
|
||
<body class="docs"><div id="layout">
|
||
<div id="layout-content"><div id="function.trim" class="refentry">
|
||
<div class="refnamediv">
|
||
<h1 class="refname">trim</h1>
|
||
<p class="verinfo">(PHP 4, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">trim</span> — <span class="dc-title">去除字符串首尾处的空白字符（或者其他字符）</span></p>
|
||
|
||
</div>
|
||
|
||
<div class="refsect1 description" id="refsect1-function.trim-description">
|
||
<h3 class="title">说明</h3>
|
||
<div class="methodsynopsis dc-description">
|
||
<span class="methodname"><strong>trim</strong></span>
|
||
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$str</code></span>
|
||
[, <span class="methodparam"><span class="type">string</span> <code class="parameter">$character_mask</code><span class="initializer"> = " \t\n\r\0\x0B"</span></span>
|
||
] ) : <span class="type">string</span></div>
|
||
|
||
<p class="para rdfs-comment">
|
||
此函数返回字符串 <code class="parameter">str</code> 去除首尾空白字符后的结果。如果不指定第二个参数，<span class="function"><strong>trim()</strong></span> 将去除这些字符：
|
||
|
||
<ul class="itemizedlist">
|
||
<li class="listitem">
|
||
<span class="simpara">
|
||
" " (<acronym title="American Standard Code for Information Interchange">ASCII</acronym> <em>32</em>
|
||
(<em>0x20</em>))，普通空格符。
|
||
</span>
|
||
</li>
|
||
<li class="listitem">
|
||
<span class="simpara">
|
||
"\t" (<acronym title="American Standard Code for Information Interchange">ASCII</acronym> <em>9</em>
|
||
(<em>0x09</em>))，制表符。
|
||
</span>
|
||
</li>
|
||
<li class="listitem">
|
||
<span class="simpara">
|
||
"\n" (<acronym title="American Standard Code for Information Interchange">ASCII</acronym> <em>10</em>
|
||
(<em>0x0A</em>))，换行符。
|
||
</span>
|
||
</li>
|
||
<li class="listitem">
|
||
<span class="simpara">
|
||
"\r" (<acronym title="American Standard Code for Information Interchange">ASCII</acronym> <em>13</em>
|
||
(<em>0x0D</em>))，回车符。
|
||
</span>
|
||
</li>
|
||
<li class="listitem">
|
||
<span class="simpara">
|
||
"\0" (<acronym title="American Standard Code for Information Interchange">ASCII</acronym> <em>0</em>
|
||
(<em>0x00</em>))，空字节符。
|
||
</span>
|
||
</li>
|
||
<li class="listitem">
|
||
<span class="simpara">
|
||
"\x0B" (<acronym title="American Standard Code for Information Interchange">ASCII</acronym> <em>11</em>
|
||
(<em>0x0B</em>))，垂直制表符。
|
||
</span>
|
||
</li>
|
||
</ul>
|
||
</p>
|
||
</div>
|
||
|
||
|
||
<div class="refsect1 parameters" id="refsect1-function.trim-parameters">
|
||
<h3 class="title">参数</h3>
|
||
<p class="para">
|
||
<dl>
|
||
|
||
|
||
<dt>
|
||
<code class="parameter">str</code></dt>
|
||
|
||
<dd>
|
||
|
||
<p class="para">
|
||
待处理的<span class="type"><span class="type 字符串">字符串</span></span>。
|
||
</p>
|
||
</dd>
|
||
|
||
|
||
|
||
<dt>
|
||
<code class="parameter">character_mask</code></dt>
|
||
|
||
<dd>
|
||
|
||
<p class="para">
|
||
可选参数，过滤字符也可由 <code class="parameter">character_mask</code> 参数指定。一般要列出所有希望过滤的字符，也可以使用 “<em>..</em>” 列出一个字符范围。
|
||
</p>
|
||
</dd>
|
||
|
||
|
||
</dl>
|
||
|
||
</p>
|
||
</div>
|
||
|
||
|
||
<div class="refsect1 returnvalues" id="refsect1-function.trim-returnvalues">
|
||
<h3 class="title">返回值</h3>
|
||
<p class="para">
|
||
过滤后的字符串。
|
||
</p>
|
||
</div>
|
||
|
||
|
||
<div class="refsect1 examples" id="refsect1-function.trim-examples">
|
||
<h3 class="title">范例</h3>
|
||
<p class="para">
|
||
<div class="example" id="example-6000">
|
||
<p><strong>Example #1 <span class="function"><strong>trim()</strong></span> 使用范例</strong></p>
|
||
<div class="example-contents">
|
||
<div class="phpcode"><pre><span style="color: #000000">
|
||
<span style="color: #0000BB"><?php<br /><br />$text </span><span style="color: #007700">= </span><span style="color: #DD0000">"\t\tThese are a few words :) ... "</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$binary </span><span style="color: #007700">= </span><span style="color: #DD0000">"\x09Example string\x0A"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$hello </span><span style="color: #007700">= </span><span style="color: #DD0000">"Hello World"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$text</span><span style="color: #007700">, </span><span style="color: #0000BB">$binary</span><span style="color: #007700">, </span><span style="color: #0000BB">$hello</span><span style="color: #007700">);<br /><br />print </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br /><br /></span><span style="color: #0000BB">$trimmed </span><span style="color: #007700">= </span><span style="color: #0000BB">trim</span><span style="color: #007700">(</span><span style="color: #0000BB">$text</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$trimmed</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$trimmed </span><span style="color: #007700">= </span><span style="color: #0000BB">trim</span><span style="color: #007700">(</span><span style="color: #0000BB">$text</span><span style="color: #007700">, </span><span style="color: #DD0000">" \t."</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$trimmed</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$trimmed </span><span style="color: #007700">= </span><span style="color: #0000BB">trim</span><span style="color: #007700">(</span><span style="color: #0000BB">$hello</span><span style="color: #007700">, </span><span style="color: #DD0000">"Hdle"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$trimmed</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// 清除 $binary 首位的 ASCII 控制字符<br />// （包括 0-31）<br /></span><span style="color: #0000BB">$clean </span><span style="color: #007700">= </span><span style="color: #0000BB">trim</span><span style="color: #007700">(</span><span style="color: #0000BB">$binary</span><span style="color: #007700">, </span><span style="color: #DD0000">"\x00..\x1F"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$clean</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">?></span>
|
||
</span>
|
||
</pre></div>
|
||
</div>
|
||
|
||
<div class="example-contents"><p>以上例程会输出：</p></div>
|
||
<div class="example-contents screen">
|
||
<div class="cdata"><pre>
|
||
string(32) " These are a few words :) ... "
|
||
string(16) " Example string
|
||
"
|
||
string(11) "Hello World"
|
||
|
||
string(28) "These are a few words :) ..."
|
||
string(24) "These are a few words :)"
|
||
string(5) "o Wor"
|
||
string(14) "Example string"
|
||
</pre></div>
|
||
</div>
|
||
</div>
|
||
</p>
|
||
<p class="para">
|
||
<div class="example" id="example-6001">
|
||
<p><strong>Example #2 使用 <span class="function"><strong>trim()</strong></span> 清理数组值</strong></p>
|
||
<div class="example-contents">
|
||
<div class="phpcode"><pre><span style="color: #000000">
|
||
<span style="color: #0000BB"><?php<br /></span><span style="color: #007700">function </span><span style="color: #0000BB">trim_value</span><span style="color: #007700">(&</span><span style="color: #0000BB">$value</span><span style="color: #007700">) <br />{ <br /> </span><span style="color: #0000BB">$value </span><span style="color: #007700">= </span><span style="color: #0000BB">trim</span><span style="color: #007700">(</span><span style="color: #0000BB">$value</span><span style="color: #007700">); <br />}<br /><br /></span><span style="color: #0000BB">$fruit </span><span style="color: #007700">= array(</span><span style="color: #DD0000">'apple'</span><span style="color: #007700">,</span><span style="color: #DD0000">'banana '</span><span style="color: #007700">, </span><span style="color: #DD0000">' cranberry '</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$fruit</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">array_walk</span><span style="color: #007700">(</span><span style="color: #0000BB">$fruit</span><span style="color: #007700">, </span><span style="color: #DD0000">'trim_value'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$fruit</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">?></span>
|
||
</span>
|
||
</pre></div>
|
||
</div>
|
||
|
||
<div class="example-contents"><p>以上例程会输出：</p></div>
|
||
<div class="example-contents screen">
|
||
<div class="cdata"><pre>
|
||
array(3) {
|
||
[0]=>
|
||
string(5) "apple"
|
||
[1]=>
|
||
string(7) "banana "
|
||
[2]=>
|
||
string(11) " cranberry "
|
||
}
|
||
array(3) {
|
||
[0]=>
|
||
string(5) "apple"
|
||
[1]=>
|
||
string(6) "banana"
|
||
[2]=>
|
||
string(9) "cranberry"
|
||
}
|
||
|
||
</pre></div>
|
||
</div>
|
||
</div>
|
||
</p>
|
||
</div>
|
||
|
||
|
||
|
||
<div class="refsect1 notes" id="refsect1-function.trim-notes">
|
||
<h3 class="title">注释</h3>
|
||
<blockquote class="note"><p><strong class="note">Note</strong>:
|
||
<strong>Possible gotcha: removing middle characters</strong><br />
|
||
<p class="para">
|
||
Because <span class="function"><strong>trim()</strong></span> trims characters from the beginning and end of
|
||
a <span class="type"><a href="language.types.string.html" class="type string">string</a></span>, it may be confusing when characters are (or are not) removed from
|
||
the middle. <em>trim('abc', 'bad')</em> removes both 'a' and 'b' because it
|
||
trims 'a' thus moving 'b' to the beginning to also be trimmed. So, this is why it "works"
|
||
whereas <em>trim('abc', 'b')</em> seemingly does not.
|
||
</p>
|
||
</p></blockquote>
|
||
</div>
|
||
|
||
|
||
<div class="refsect1 seealso" id="refsect1-function.trim-seealso">
|
||
<h3 class="title">参见</h3>
|
||
<p class="para">
|
||
<ul class="simplelist">
|
||
<li class="member"><span class="function"><a href="ltrim.html" class="function" rel="rdfs-seeAlso">ltrim()</a> - 删除字符串开头的空白字符（或其他字符）</span></li>
|
||
<li class="member"><span class="function"><a href="rtrim.html" class="function" rel="rdfs-seeAlso">rtrim()</a> - 删除字符串末端的空白字符（或者其他字符）</span></li>
|
||
<li class="member"><span class="function"><a href="str_replace.html" class="function" rel="rdfs-seeAlso">str_replace()</a> - 子字符串替换</span></li>
|
||
</ul>
|
||
</p>
|
||
</div>
|
||
|
||
</div></div></div></body></html> |