Application scenarios of anti-regular expressions in Go language

Reverse regular expression application scenarios in Go language

As a powerful text matching and processing tool, regular expressions have been widely used in various fields. As a programming language with high development efficiency, fast execution speed and strong portability, Go language also comes with its own support for regular expressions. However, in addition to regular expressions, the Go language also provides another powerful tool-negative regular expression. Let's discuss the application scenarios of anti-regular expressions in Go language.

1. Filtering illegal characters

In development, text input restrictions are often imposed. For example, only specific characters such as numbers and letters can be entered. At this time, you can use Anyway expression to achieve. Suppose we need to restrict the input text from containing Chinese characters, punctuation marks, and spaces. We can use the following regular expressions for matching:

^[a-zA-Z0-9]*$

where "^" represents the beginning of the text, and "$" represents the end of the text. "*" means matching any number of the preceding characters, "[a-zA-Z0-9]" means matching all numbers and letters. If you need to check whether the input text is illegal, you only need to reverse the regular expression to get the following inverse regular expression:

[^a-zA-Z0-9]+

where "[]" represents the matching character set, and "^" represents the negative character set , " " means match at least one previous character. The meaning of this inverse regular expression is to match all characters that are not numbers and letters. If you use this inverse regular expression to match text, as long as it can be matched, it can be determined to be an illegal character.

2. Check whether the text contains certain characters

In some scenarios, you may need to check whether the text contains certain characters, and if so, perform specific processing. Otherwise skip it. For example, when processing HTML text, you may need to check whether it contains Javascript code. At this time, you can use anti-regular expressions to check.

Suppose we want to check whether the text contains Javascript code, you can use the following anti-regular expression:

<script[^<]*(?:(?!</script>)<[^<]*)*</script>

This anti-regular expression means to match everything starting with "

3. Filter sensitive information

In some scenarios, it may be necessary to filter sensitive information in text, such as phone numbers, ID numbers, etc. At this time, you can use anti-regular expressions to match these sensitive information and replace or delete them.

Suppose we want to filter phone numbers, we can use the following inverse regular expression:

(d{3})d{4}(d{4})

This inverse regular expression means to match all phone numbers consisting of 11 digits and combine them Divided into three parts. If you use this inverse regular expression to match and match text that meets the conditions, you can replace it with "*" or delete it.

Summary

Regular expressions have a wide range of application scenarios in the Go language, such as filtering illegal characters, checking whether the text contains certain characters, filtering sensitive information, etc. Using anti-regular expressions can effectively improve development efficiency and program readability, allowing us to process complex text data more easily.

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