简介
给定这样的字符串 -
MAX_checkTime_Hour('0,1', '=~') and (MAX_checkTime_Day('1,2', '=~') or MAX_checkTime_Day('1,2', '=~')) and MAX_checkGeo_Country('DZ,AO,BJ)
我想在and MAX_或and (MAX_或and ((MAX_等模式之前和之间插入<br />标签，以便输出是 -
MAX_checkTime_Hour('0,1', '=~')<br /> and <br />(MAX_checkTime_Day('1,2', '=~') or MAX_checkTime_Day('1,2', '=~'))<br /> and <br />MAX_checkGeo_Country('DZ,AO,BJ)
到目前为止
我做了什么有了下面的正则表达式替换，我几乎就在那里。插入<br />标签是有效的，但我必须插入固定数量的 -
preg_replace("/'s+and's+MAX_/",'<br /> and <br />MAX_',$str);
我想——
- 保留空格的确切数量。
- 保留
MAX_之前第一个括号的确切数量。
所以，如果原始字符串是这样的——
MAX_checkTime_Hour('0,1', '=~') <3 white spaces here> and <5 white spaces here> #2 first brackets here#MAX_checkTime_Day('1,2', '=~')
我希望输出是 -
MAX_checkTime_Hour('0,1', '=~')<br /> <3 white spaces here> and <5 white spaces here> <br /><first brackets here>MAX_checkTime_Day('1,2', '=~')
更新
我尝试了以下内容，假设可变数量的空格将存储在变量中，但它不起作用 -
preg_replace("/{'s+}and{'s+}MAX_/",'<br />$1and$2<br />MAX_',$str);
我想你忘记了源中的"or"运算符（位于第三个MAX_之前）。正则表达式的alt.版本-它更通用（因为它可以匹配并安全地替换"and"和"or"运算符），并且进行了更多的优化（因为它不使用前瞻/后视语法）：
$result = preg_replace('/('s+(and|or)'s+)('(*MAX_)/', '<br/>$1<br/>$2', $str);
此外，它与 DRY 兼容，替换字符串不包含源字符串的任何部分
试试这个：
$result = preg_replace('/(?<=and)(?=['s(]+MAX_)/im', '<br />and<br />MAX_''', $subject);
正则表达式解释
<!--
(?<=and)(?=['s'(]+MAX_)
Options: case insensitive; ^ and $ match at line breaks
Assert that the regex below can be matched, with the match ending at this position (positive lookbehind) «(?<=and)»
Match the characters “and” literally «and»
Assert that the regex below can be matched, starting at this position (positive lookahead) «(?=['s'(]+MAX_)»
Match a single character present in the list below «['s'(]+»
Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
A whitespace character (spaces, tabs, and line breaks) «'s»
A ( character «'(»
Match the characters “MAX_” literally «MAX_»
-->
怎么样：
$str = "MAX_checkTime_Hour('0,1', '=~') and (MAX_checkTime_Day('1,2', '=~') or MAX_checkTime_Day('1,2', '=~')) and MAX_checkGeo_Country('DZ,AO,BJ)";
echo preg_replace("/('s+)and('s+)('(*MAX_)/", "<br />$1and$2<br />$3", $str);
输出：
MAX_checkTime_Hour('0,1', '=~')<br /> and <br />(MAX_checkTime_Day('1,2', '=~') or MAX_checkTime_Day('1,2', '=~'))<br /> and <br />MAX_checkGeo_Country('DZ,AO,BJ)