Maison >développement back-end >tutoriel php >PHP函数preg_split的正确使用方法_PHP教程
对于初学者来说,大家对说明 array preg_split ( string $pattern, string $subject [, int $limit [, int $flags]] )
返回一个数组,包含 subject 中沿着与 pattern 匹配的边界所分割的子串。
如果指定了 limit,则最多返回 limit 个子串,如果 limit 是 -1,则意味着没有限制,可以用来继续指定可选参数 flags。
flags 可以是下列标记的任意组合(用按位或运算符 | 组合):
PREG_SPLIT_NO_EMPTY
如果设定了本标记,则 preg_split() 只返回非空的成分。
PREG_SPLIT_DELIM_CAPTURE
如果设定了本标记,定界符模式中的括号表达式也会被捕获并返回。本标记添加于 PHP 4.0.5。
PREG_SPLIT_OFFSET_CAPTURE
如果设定了本标记,如果设定本标记,对每个出现的匹配结果也同时返回其附属的字符串偏移量。注意这改变了返回的数组的值,使其中的每个单元也是一个数组,其中第一项为匹配字符串,第二项为其在 subject 中的偏移量。本标记自 PHP 4.3.0 起可用。
提示
如果不需要正则表达式的功能,可以选择使用更快(也更简单)的替代函数如 explode() 或 str_split()。
例 1672. PHP函数preg_split例子:取得搜索字符串的成分
<ol class="dp-xml"> <li class="alt"><span><span>// split the phrase by any number of commas or space characters, </span></span></li> <li><span>// which include " ", r, t, n and f </span></li> <li class="alt"> <span>$</span><span class="attribute">keywords</span><span> = </span><span class="attribute-value">preg_split</span><span> ("/[s,]+/", "hypertext language, programming"); </span> </li> <li> <span class="tag">?></span><span> </span> </li> </ol>
例 1673.PHP函数preg_split 将字符串分割成字符
<ol class="dp-xml"> <li class="alt"><span><span>$</span><span class="attribute">str</span><span> = </span><span class="attribute-value">'string'</span><span>; </span></span></li> <li> <span>$</span><span class="attribute">chars</span><span> = </span><span class="attribute-value">preg_split</span><span>('//', $str, -1, PREG_SPLIT_NO_EMPTY); </span> </li> <li class="alt"><span>print_r($chars); </span></li> <li> <span class="tag">?></span><span> </span> </li> </ol>
例 1674. PHP函数preg_split将字符串分割为匹配项及其偏移量
<ol class="dp-xml"> <li class="alt"><span><span>$</span><span class="attribute">str</span><span> = </span><span class="attribute-value">'string'</span><span>; </span></span></li> <li> <span>$</span><span class="attribute">chars</span><span> = </span><span class="attribute-value">preg_split</span><span>('//', $str, -1, PREG_SPLIT_NO_EMPTY); </span> </li> <li class="alt"><span>print_r($chars); </span></li> <li> <span class="tag">?></span><span> </span> </li> </ol>
PHP函数preg_split例子将输出:
<ol class="dp-xml"> <li class="alt"><span><span>Array( [0] =</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span><span>Array ( [0] =</span><span class="tag">></span><span> hypertext [1] =</span><span class="tag">></span><span> 0 ) [1] =</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span><span>Array ( [0] =</span><span class="tag">></span><span> language [1] =</span><span class="tag">></span><span> 10 ) [2] =</span><span class="tag">></span><span> </span></span></li> <li class="alt"> <span><span>Array ( [0] =</span><span class="tag">></span><span> programming [1] =</span><span class="tag">></span><span> 19 </span></span><span><span>)</span></span><span><span>) </span></span> </li> </ol>