Question

我对正则表达式非常不熟悉，所以我不知道从哪里开始。我需要在文件中存储时间范围值。我想在保存之前对正则表达式进行验证。

格式必须是：

00:00-00:00

其中数字的最小值可以是0，最大值可以表示为

23:59-23:59

如何确保字符串符合此约束？

Answer 1

试试这个

\b((?:(?:[01][0-9]|2[0-3]):(?:[0-5][0-9]))-(?:(?:[01][0-9]|2[0-3]):(?:[0-5][0-9])))\b

<强>解释

\b                   # Assert position at a word boundary
(                    # Match the regular expression below and capture its match into backreference number 1
   (?:                  # Match the regular expression below
      (?:                  # Match the regular expression below
                              # Match either the regular expression below (attempting the next alternative only if this one fails)
            [01]                 # Match a single character present in the list “01”
            [0-9]                # Match a single character in the range between “0” and “9”
         |                    # Or match regular expression number 2 below (the entire group fails if this one fails to match)
            2                    # Match the character “2” literally
            [0-3]                # Match a single character in the range between “0” and “3”
      )
      :                    # Match the character “:” literally
      (?:                  # Match the regular expression below
         [0-5]                # Match a single character in the range between “0” and “5”
         [0-9]                # Match a single character in the range between “0” and “9”
      )
   )
   -                    # Match the character “-” literally
   (?:                  # Match the regular expression below
      (?:                  # Match the regular expression below
                              # Match either the regular expression below (attempting the next alternative only if this one fails)
            [01]                 # Match a single character present in the list “01”
            [0-9]                # Match a single character in the range between “0” and “9”
         |                    # Or match regular expression number 2 below (the entire group fails if this one fails to match)
            2                    # Match the character “2” literally
            [0-3]                # Match a single character in the range between “0” and “3”
      )
      :                    # Match the character “:” literally
      (?:                  # Match the regular expression below
         [0-5]                # Match a single character in the range between “0” and “5”
         [0-9]                # Match a single character in the range between “0” and “9”
      )
   )
)
\b                   # Assert position at a word boundary

什么是正则表达式以确保字符串是给定的格式？

1 个答案: