PHP 删除前面的所有字符，最后一个数字除外

Question

我有这个php代码：

$test = "http://cp.dmbshare.net:8000/hls/niehaus/niehaus/1822/1822_1139.ts";

我只想要数字1139.但是我找不到如何处理preg_replace。我做了一些图案，但我不能做我想做的事。

有人可以帮助我吗？

Answer 1

preg_match('/(d+).ts$/', $test, $matches);
echo $matches[1];

Answer 2

将问题分解为更小的部分总是更容易。

您的问题是"找到字符串中的最后一个数字"。

我建议将其分解为：

1. 查找字符串中的所有数字
2. 拿最后一个

为此，请尝试以下操作：

// match all numeric substrings
preg_match_all("/d+/",$test,$matches);
// all matches are in $matches[0]
// get last:
$lastnumber = array_pop($matches[0]);

做！看看当你分解问题时，问题是如何变得更容易的？

Answer 3

解决您问题的最佳方法如下

$test = "http://cp.dmbshare.net:8000/hls/niehaus/niehaus/1822/1822_1139.ts";
$test = preg_replace("/(?:.*)((?:_)([0-9]+))(?:.[a-z0-9]+)$/","$2",$test);
echo $test; // 1139

解释

(
    ?: Non-capturing group. Groups multiple tokens together without creating a capture group.
    . Dot. Matches any character except line breaks.
    * Star. Match 0 or more of the preceding token.
)
(
    Capturing group #1. Groups multiple tokens together and creates a capture group for extracting a substring or using a backreference.
    (
        ?: Non-capturing group. Groups multiple tokens together without creating a capture group.
        _ Escaped character. Matches a "_" character (char code 95).
    )
    (
        Capturing group #2. Groups multiple tokens together and creates a capture group for extracting a substring or using a backreference.
        [ Character set. Match any character in the set.
        0-9 Range. Matches a character in the range "0" to "9" (char code 48 to 57).
        ]
        + Plus. Match 1 or more of the preceding token.
    )
)
(
    ?: Non-capturing group. Groups multiple tokens together without creating a capture group.
    . Escaped character. Matches a "." character (char code 46).
    [ Character set. Match any character in the set.
    a-z Range. Matches a character in the range "a" to "z" (char code 97 to 122).
    ]
    + Plus. Match 1 or more of the preceding token.
)
$ End. Matches the end of the string, or the end of a line if the multiline flag (m) is enabled.