Question

在PHP中使用preg_replace时，是否可以获取匹配数并将其传递给preg_replace的第二个参数。

我正在尝试做的例子：

$str = <<<EOF
*Samsung
This is the description text for Samsung
**Early years
Korean town
***Founders
EOF;

echo preg_replace('/(?m)^\*{1,3}([^*].*)$/', '<h {} >$1</h {}>', $str);
//Note the {} in the above. That's where the count from the regex needs to go. So we'll be create H tags based on the replacements.

所以最终输出将是：

<h1>Samsung</h1> // There was one `*` here
This is the description text for Samsung
<h2>Early years</h2> // There were two `*`s here
Korean town
<h3>Founders</h3> // There were three `*`s here

这样的事情可能吗？可以从正则表达式中提取计数吗？

Answer 1

如建议使用回调来执行此操作。你可以根据自己的需要调整它......

$str = preg_replace_callback('~(?m)^(\*{1,3})([^*].*)$~', 
     function($m) {
         $count = strlen($m[1]);
         return "<h$count>$m[2]</h$count>";
     }, $str);

Answer 2

TRY

$str = <<<EOF
*Samsung
This is the description text for Samsung
**Early years
Korean town
***Founders
EOF;
function turnStarToHeader($m) {
    static $id = 0;
    $id++;
    return "<h$id>$m[1]</h$id>";
 }

echo preg_replace_callback('/(?m)^\*{1,3}([^*].*)$/', 'turnStarToHeader', $str);

preg_replace将匹配的次数传递给第二个参数

2 个答案: