正则表达式匹配带有符号的字母和数字

Question

对于PHP的preg_match，我尝试将元素符号匹配为

K+ => array( [0] => K+, [1] => K, [2] => +)
Cr7+ => array( [0] => Cr7+, [1] => Cr, [2] => 7+)
O2- => array( [0] => O2-, [1] => O, [2] => 2-)

我想出了一个正则表达式

preg_match('/^[A-Za-z](\d[+|-])/', $str, $match);

但不匹配 K+。我怎样才能将 OR 条件也添加到数字？

Answer 1

您可以匹配一个大写字母跟在可选的小写字母后面，表示以数字或 [-+] 符号或两者结尾的元素名称，使用：

([A-Z][a-z]*)(\d*[-+]?)

RegEx live demo

PHP 代码（参见演示 here）：

preg_match_all('~([A-Z][a-z]*)(\d*[-+]?)~', $str, $matches);

所提供输入的输出：

Array
(
    [0] => Array
        (
            [0] => K+
            [1] => K
            [2] => +
        )

    [1] => Array
        (
            [0] => Cr7+
            [1] => Cr
            [2] => 7+
        )

    [2] => Array
        (
            [0] => O2-
            [1] => O
            [2] => 2-
        )

)

正则表达式匹配带有符号的字母和数字

regex matching letters and digits with signs

regex

preg-match