php 如何在 preg_match 中使用可变模式？
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How do I use a variable pattern with preg_match?
提问by homework
I don't know if this is enough data to feed off of, but I have
我不知道这是否足以提供足够的数据，但我有
preg_match('/SAMPLETEXT/', $bcurl, $cookie1);
preg_match('/SAMPLETEXT/', $bcurl, $cookie1);
and I was wondering if I can make it
我想知道我能不能做到
preg_match($newfunction, $bcurl, $cookie1);
preg_match($newfunction, $bcurl, $cookie1);
but when I do, I get this error "Warning: preg_match() [function.preg-match]: Delimiter must not be alphanumeric or backslash in".
但是当我这样做时，我收到此错误“警告：preg_match() [function.preg-match]：分隔符不能是字母数字或反斜杠”。
How can I make it check for my new function, rather than have it check just for "SAMPLETEXT".
我怎样才能让它检查我的新功能，而不是让它只检查“SAMPLETEXT”。
回答by ysth
Try preg_match("/$newfunction/", $bcurl, $cookie1);so that you are providing the required delimiters (using a delimiter that isn't going to be in $newfunction).
尝试preg_match("/$newfunction/", $bcurl, $cookie1);提供所需的分隔符（使用不在 $newfunction 中的分隔符）。
But note that the documentationsays "Do not use preg_match() if you only want to check if one string is contained in another string. Use strpos() or strstr() instead as they will be faster."
但请注意，文档说“如果您只想检查一个字符串是否包含在另一个字符串中，请不要使用 preg_match()。使用 strpos() 或 strstr() 代替，因为它们会更快。”
回答by Vincent
preg_match('/'.$pattern.'/i', $subject)
preg_match('/'.$pattern.'/i', $subject)
ioption: allow capital letters or hyphen.
i选项：允许大写字母或连字符。
回答by r7eem
u can use variable by putting it between []
您可以通过将变量放在 [] 之间来使用它
$subject = "abcdef";
$ch = 'b';
$pattern = '/[$ch]/';
preg_match($pattern, $subject, $matches);
//print_r($matches);
if ($matches)
{
echo $subject;
}
