What are the regular expressions to cultivate?

Cultivating regular expressions requires mastering basic syntax, character classes, quantifiers, boundary matching, grouping and referencing, greedy and non-greedy, escape characters, common techniques, etc. Detailed introduction: 1. Basic syntax: Understand the meaning of the basic syntax metacharacters and special characters of regular expressions, such as . represents any character, \d represents numbers, \w represents letters, numbers and underscores, etc.; 2. Character classes: master How to use character classes to match a specific set of characters, such as [abc] can match the characters a, b or c, [^abc] can match any character except a, b and c, etc.

To master regular expressions, you need to master the following aspects:

1. Basic grammar: Understand the basic syntax metacharacters and the meaning of special characters of regular expressions , such as . represents any character, \d represents numbers, \w represents letters, numbers and underlines, etc.

2. Character classes: Master how to use character classes to match specific character sets. For example, [abc] can match characters a, b or c, [^abc] can match characters other than a and b. and any character other than c.

3. Quantifiers: Learn how to use quantifiers to specify the number of matches. For example, * means matching 0 or more times, means matching 1 or more times, ? means matching 0 or 1 times. , {n} means matching exactly n times, {n,} means matching at least n times, {n,m} means matching at least n times and no more than m times.

4. Boundary matching: Master how to use boundary matching to limit the matching position, such as ^ means matching the beginning of the string, $ means matching the end of the string, \b means matching the boundary of the word .

5. Group and reference: Learn how to use grouping and reference to extract and repeat matched content, such as (abc) to match abc as a whole, (abc)\1 to match Two consecutive abc.

6. Greedy and non-greedy: Understand the difference between greedy and non-greedy matching. Greedy matching matches as much as possible, and non-greedy matching matches as little as possible. You can add it after the quantifier ?To achieve non-greedy matching.

7. Escape characters: Learn how to use escape characters to match the special characters themselves, such as \. to match periods and \( to match left brackets.

8. Common skills: Understand some common regular expression skills, such as using capture groups to extract matching content, using zero-width assertions for advanced matching, using pattern modifiers to set matching options, etc.

Through learning and practice, you can gradually accumulate experience and continuously improve your understanding and application ability of regular expressions, so that you can better master and cultivate regular expressions.

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