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[1013] Understanding the pattern ".*" in regular expression

 My understanding:

  • * means that the preceding character can appear zero or more times
  • .* can match .........., etc. It means it can match any sequence of characters, because the . can match any character. 

In regular expressions, the pattern .* has a specific meaning:

  • The dot (.) represents any character except line terminators (such as newline characters).
  • The asterisk (*) following the dot means that the preceding character (in this case, the dot) can appear zero or more times.

In other words, .* matches any sequence of characters, including an empty string. It’s a powerful construct for capturing variable-length content within a larger pattern.

For example:

  • /a.*b/ matches any string that starts with ‘a’ and ends with ‘b’, with any characters (including none) in between.
  • /.*foo/ matches any string that ends with ‘foo’, regardless of what comes before it.

Remember that by default, quantifiers like the asterisk are “greedy”, meaning they try to match as much of the string as possible. If you want a “non-greedy” match (stopping as soon as a match is found), you can use .*? instead.

Feel free to experiment with this pattern in your regular expressions! 😊 12

posted on 2024-06-19 14:20  McDelfino  阅读(2)  评论(0编辑  收藏  举报