Regex Notes

Here’s a structured roadmap to help you learn regex (regular expressions) from beginner to advanced, guiding you through each phase until you're able to write complex regex patterns.

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Beginner Level: Core Concepts

1. What is Regex?
2. Literal Characters
3. Meta-characters
4. Quantifiers
5. Escaping Special Characters
6. Anchors

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Intermediate Level: Building Efficiency

1. Grouping and Capturing
2. Non-capturing Groups
3. Alternation
4. Boundaries
5. Lookahead and Lookbehind (Zero-width Assertions)
6. Greedy vs Lazy Matching
7. Flags/Modifiers

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Advanced Level: Mastery and Industry-level Patterns

1. Recursive Patterns
2. Backreferences
3. Conditionals in Regex
4. Unicode and Extended Character Sets
5. POSIX Character Classes
6. Atomic Groups
7. Advanced Lookahead/Lookbehind
8. Regex Performance Optimization
9. Regex in Different Languages/Tools
10. Creating Industry-level Solutions
    • Validation Patterns
    • Search Algorithms
11. Regex Debugging Tools

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Project and Practice

• Build projects using regex to parse text, validate inputs, and filter large data efficiently.
• Regularly practice by writing complex validation and parsing patterns.

By mastering these topics step by step, you will gradually move toward creating complex, high-performance regex patterns like those used in large-scale applications such as YouTube’s search algorithms.