例:
<style> .word-0{ background-color: yellow; } .word-1{ border:1px solid red; } </style> <?php header('Content-type:text/html;charset=utf-8'); /* 标记Web页面 */ $body = ' <p>I like pickles and hrrring.</p> <a href="pickle.php"><img width="200" src="pickle.png">A pickle pic</a> I have herringbone-patterned toaster cozy. <herring>Herring is not a real HTML element!</herring> '; $words = array('pickle', 'herring'); $replacements = array(); foreach($words as $i => $word) { $replacements[] = "<span class='word-$i'>$word</span>"; } // 将页面分解为多个块 // 由看上去类似HTML元素的部分分隔 $parts = preg_split("{(<(?:"[^"]*"|'[^']*'|[^'">])*>)}", $body, -1, PREG_SPLIT_DELIM_CAPTURE); //var_dump($parts); /* array (size=15) 0 => string ' ' (length=2) 1 => string '<p>' (length=3) 2 => string 'I like pickles and hrrring.' (length=27) 3 => string '</p>' (length=4) 4 => string ' ' (length=2) 5 => string '<a href="pickle.php">' (length=21) 6 => string '' (length=0) 7 => string '<img width="200" src="pickle.png">' (length=34) 8 => string 'A pickle pic' (length=12) 9 => string '</a>' (length=4) 10 => string ' I have herringbone-patterned toaster cozy. ' (length=46) 11 => string '<herring>' (length=9) 12 => string 'Herring is not a real HTML element!' (length=35) 13 => string '</herring>' (length=10) 14 => string ' ' (length=2) */ foreach($parts as $i => $part) { //如果这个部分是HTML元素则跳过 if(isset($part[0]) && ($part[0] == '<')) { continue; } //将这些单词用<span/>包围起来 $parts[$i] = str_replace($words, $replacements, $part); } $body = implode('', $parts); echo $body;
说明:
preg_split() 函数中使用的正则表达式匹配 HTML 标签
<(?:"[^"]*"|'[^']*'|[^'">])*>
可以这样理解:
< //开始尖括号 (?: //任意数量的 "[^"]*" //双引号字符串 | //或 '[^']*' //单引号字符串 | //或 [^'">] //除去单引号、双引号和>的其他文本 )* > //结束尖括号
但是这种方法无法高亮最后一个 Herring,因为它的首字母是大写的。要完全不区分大小写的更改,需要把 str_replace() 方法 改为 preg_replace() 方法:
<style> .word-0{ background-color: yellow; } .word-1{ border:1px solid red; } </style> <?php header('Content-type:text/html;charset=utf-8'); /* 标记Web页面 */ $body = ' <p>I like pickles and hrrring.</p> <a href="pickle.php"><img width="200" src="pickle.png">A pickle pic</a> I have herringbone-patterned toaster cozy. <herring>Herring is not a real HTML element!</herring> '; $words = array('pickle', 'herring'); $replacements = array(); foreach($words as $i => $word) { $patterns[] = '/'.preg_quote($word).'/i'; //preg_quote()需要参数 str 并向其中 每个正则表达式语法中的字符前增加一个反斜线。正则表达式特殊字符有: . + * ? [ ^ ] $ ( ) { } = ! < > | : - $replacements[] = "<span class='word-$i'>\0</span>"; } // 将页面分解为多个块 // 由看上去类似HTML元素的部分分隔 $parts = preg_split("{(<(?:"[^"]*"|'[^']*'|[^'">])*>)}", $body, -1, PREG_SPLIT_DELIM_CAPTURE); var_dump($parts); /* array (size=15) 0 => string ' ' (length=2) 1 => string '<p>' (length=3) 2 => string 'I like pickles and hrrring.' (length=27) 3 => string '</p>' (length=4) 4 => string ' ' (length=2) 5 => string '<a href="pickle.php">' (length=21) 6 => string '' (length=0) 7 => string '<img width="200" src="pickle.png">' (length=34) 8 => string 'A pickle pic' (length=12) 9 => string '</a>' (length=4) 10 => string ' I have herringbone-patterned toaster cozy. ' (length=46) 11 => string '<herring>' (length=9) 12 => string 'Herring is not a real HTML element!' (length=35) 13 => string '</herring>' (length=10) 14 => string ' ' (length=2) */ foreach($parts as $i => $part) { //如果这个部分是HTML元素则跳过 if(isset($part[0]) && ($part[0] == '<')) { continue; } //将这些单词用<span/>包围起来 $parts[$i] = preg_replace($patterns, $replacements, $part); } $body = implode('', $parts); echo $body;
参考:
<PHP Cookbook>3'rd
《精通正则表达式》第3版