Question

我有正则表达式

eregi_replace("s=.*&","",$section->urlToThreads);

它的作用是用''替换所有内容，该内容以's='开头，以'&'

结尾

我想做的也是“＆amp;”在's ='后直到字符串结尾才找到，然后用''

替换's ='到字符串结尾的所有内容

E.g。

test.php？s = 12232dsd23423＆amp; t = 41 会变成 test.php？t = 41

和

test.php？t = 41＆amp; s = 12232dsd23423 会变成 test.php？t = 41

Answer 1

您可以将&设为可选，并且仅允许非&字符匹配。另外，使用单词边界只匹配s=（而不是links=的子字符串）：

"\bs=[^&]*&?"

但你不应该再使用ereg了。更新至preg：

$result = preg_replace('/\bs=[^&]*&?/', '', $section->urlToThreads);

Answer 2

解决方案 - 没有REGEX

$str = $section->urlToThreads;
                        $url = '';
                        $url = $section->urlToThreads;
                        $pos = strpos( $str,'s=');
                        if ($pos)
                        {
                            $pos_ampersand =  strpos( $str,'&',$pos);

                            if ($pos_ampersand) //if ampersand is found after s=
                            {
                                $url = substr($str, 0, $pos) . substr($str, $pos_ampersand+1, strlen($str));
                            }
                            else // if no ampersand found after s=
                            {
                                $url = substr($str, 0, $pos-1);
                            }
                        }
                        $section->urlToThreads = $url;

Answer 3

如果是preg_replace我会这样做：

preg_replace('@(\?)s(=[^&]*)?&?|&s(=[^&]*)?@', '\\1', $section->urlToThreads);

一些测试：

$tests = array(
    'test.php?s',
    'test.php?s=1',
    'test.php?as=1',
    'test.php?s&as=1',
    'test.php?s=1&as=1',
    'test.php?as=1&s',
    'test.php?as=1&s=1',
    'test.php?as=1&s&bs=1',
    'test.php?as=1&s=1&bs=1'
);
foreach($tests as $test){
    echo sprintf("%-22s -> %-22s\n", $test, preg_replace('@(\?)s(=[^&]*)?&?|&s(=[^&]*)?@', '\\1', $test));
}

输出：

test.php?s             -> test.php?
test.php?s=1           -> test.php?
test.php?as=1          -> test.php?as=1
test.php?s&as=1        -> test.php?as=1
test.php?s=1&as=1      -> test.php?as=1
test.php?as=1&s        -> test.php?as=1
test.php?as=1&s=1      -> test.php?as=1
test.php?as=1&s&bs=1   -> test.php?as=1&bs=1
test.php?as=1&s=1&bs=1 -> test.php?as=1&bs=1

Answer 4

s=.*(?:&|$)检查& 或行/字符串的结尾。

如果＆amp;最后没有找到然后更换一切

4 个答案: