How can I Use Hyphens Correctly in Regular Expression Character Classes?

The competence in the regular expression match

When using regular expressions, be sure to consider the behavior of various characters. In this example, let's discuss how to handle the characters.

Question:

How to modify the existing mode

to match the character matching?

[a-zA-Z0-9!$*trn] Answer:

Understand the characters in the regular expression

Usually, even characters act as ordinary characters in regular expression. However, when they appear in the character class and there are other characters in front and behind, their behavior will change slightly. In these specific circumstances, they have special uses.

matching the character

[]

To match the company, you can choose the following options:

Directly use the characters:

The characters in the character class

indicate itself.

You can also use 🎜 义 - Example
• Consider the following scene: -

: Matching any instance of character A, B, C or connected characters.

: equivalent to .

: matching A, B, C, or connected characters. Pay attention to the position of the character.

: Specify the range from A to D, excluding the characters. Here is the interpretation of the scope indicator.
• [-abc]

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