Regular expression generator

Regular expression generator: final guide to solving complex text matching

In modern software development, Regular Expression (Regular Exchange) Almost everywhere. Whether it is the front-end form validation, the back-end log analysis or the text extraction in the data reptile, it is a necessary skill. However, the formal grammar is so obscure that it is often time-consuming to develop a model that is both efficient and correct. This generator is designed to Visualized templates, real-time testing and automatic code generation • Resolving the pains of developers when they prepare the regularity.

1. Addressing the practical question: Why can you not use just one simple rule?

Here. E-mail Authentication For example, many developers write it down. /^\w+@\w+\.\w+$/ 。 In practice, however, this leads to the following issues:

• Username with point not supported: Like [email protected] Could be a verification failure.
• Gmail with plus sign not supported: Like [email protected] 。
• Do not support multi-level domain names: Like .com.cn or .co.uk 。

Our tools are built inside. Level of production environment . Each template is tested repeatedly at the border to ensure that your data validation is rigorous and flexible, and that business logic errors due to the regular loophole are avoided.

2. Depth optimization: How can the amplifiers (Flags) be used to improve efficiency?

Understanding the amulet is key to the rule. This tool allows you to switch the usual modifiers by one key:

• g (Global): Resolves the embarrassment of " Replaces the first match only " , opening the global match.
• i (Ignore Case): The user can capture it accurately, whether it's in upper or lowercase. It's very simple. [a-zA-Z] and preparation of the report.
• m (Multiline): Jean. ^ and $ Actes at the beginning of each line, not the entire string. This is essential in the processing of multi-line log documents.
• s (dotAll): Jean. . Really matches any character, including line breaks. This is very useful when extracting multiple rows of text between HTML tabs.

3. From generation to landing: Multilingual code one key export

The right rule is only the first step, and integration into the code often involves transliteration (e.g. JavaScript) ) is a problem of double backslash. This generator supports:

1. JavaScript: Generate a font amount or RegExp Construct a function.
2. Python: Use re module compile Mode.
3. PHP: Autoprocessing preg_match requires a separator.
4. Java/Go: Presets language-specific transposition logic.

Regular proposal prepared in common scenes (FAQ)

Q: Why do my normals cause the browser to die?
A: This is usually due to Catastropic Backtrace I'm not gonna do that. When multiple nested words exist in your regular rule (e.g. (a+)+$ ) and if matching fails, the engine will try the possible path for the index level. It is recommended that the real-time testing function of this tool be used to observe the speed of matching under complex text.

Q: How do you match the non-growth pattern?
A: In-quantifiable words (e.g. * , + , {n,m} Stay close to one. ? 。 For example, <.*?> It matches the HTML label itself, and <.*> is always matched to the last closed tab on the page. Best practices for non-gretful matching are pre-set in the template library of this tool.

Q: Will the ID and cell phone numbers be obsolete?
A: With the opening of the sector (e.g. virtual operator section), the maintenance is indeed required. The template of this tool will be updated regularly to cover the latest China 11 cell phone numbers and 18 second-place IDs to check logic.