PHP 使用 RegEx 获取字符串的子串
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PHP Using RegEx to get substring of a string
提问by MonkeyBlue
I'm looking for an way to parse a substring using PHP, and have come across preg_match however I can't seem to work out the rule that I need.
我正在寻找一种使用 PHP 解析子字符串的方法，并且遇到了 preg_match 但是我似乎无法计算出我需要的规则。
I am parsing a web page and need to grab a numeric value from the string, the string is like this
我正在解析一个网页，需要从字符串中抓取一个数值，字符串是这样的
producturl.php?id=736375493?=tm
I need to be able to obtain this part of the string:
我需要能够获得字符串的这一部分：
736375493
736375493
Thanks Aaron
谢谢亚伦
回答by David Fells
$matches = array();
preg_match('/id=([0-9]+)\?/', $url, $matches);
This is safe for if the format changes. slandau's answer won't work if you ever have any other numbers in the URL.
如果格式更改，这是安全的。如果 URL 中有任何其他数字，slandau 的答案将不起作用。
回答by anubhava
<?php
$string = "producturl.php?id=736375493?=tm";
preg_match('~id=(\d+)~', $string, $m );
var_dump($m[1]); // $m[1] is your string
?>
回答by slandau
$string = "producturl.php?id=736375493?=tm";
$number = preg_replace("/[^0-9]/", '', $string);
回答by mickmackusa
Unfortunately, you have a malformed url query string, so a regex technique is most appropriate. See what I mean.
不幸的是，您有一个格式错误的 url 查询字符串，因此正则表达式技术是最合适的。见我的意思。
There is no need for capture groups. Just match id=then forget those characters with \K, then isolate the following one or more digital characters.
不需要捕获组。用 匹配id=然后忘记那些字符\K，然后隔离以下一个或多个数字字符。
Code (Demo)
代码（演示）
$str = 'producturl.php?id=736375493?=tm';
echo preg_match('~id=\K\d+~', $str, $out) ? $out[0] : 'no match';
Output:
输出：
736375493
