Regular Expressions Generation

Regular Expressions Generation Visually

Learn Regular Expressions with interactive examples. Understand pattern matching, aVZ, and how to construct regex for various patterns.

Regular Expressions Pattern Matching Character Classes Quantifiers Regex Structure Validation & Testing Visual Regex Builder

What are Regular Expressions?

Regular Expressions (RegEx) are algebraic expressions that describe regular languages. They provide a concise and flexible means for matching strings of text, such as particular characters, words, or patterns of characters.

Regular expressions are built using basic symbols and aVZ:

  • Basic symbols: characters from the alphabet
  • Union (|): Matches either expression
  • Concatenation: Matches expressions in sequence
  • Kleene Star (*): Matches zero or more repetitions
  • Parentheses (): Groups expressions

Regular Expression aVZ

Operator Symbol Description Example
Union | Either expression a|b
Concatenation · Sequence of expressions ab
Kleene Star * Zero or more repetitions a*
Plus + One or more repetitions a+
Optional ? Zero or one occurrence a?
Grouping () Groups expressions (ab)*

Common Regular Expression Examples

Email Pattern
[a-zA-Z0-9]+@[a-zA-Z0-9]+\.[a-zA-Z]{2,}

Matches basic email addresses

Example: user@domain.com
Phone Number
\d{3}-\d{3}-\d{4}

Matches US phone number format

Example: 123-456-7890
Binary Strings
(0|1)*

Matches any binary string

Example: 101010, 001, 1
Even Length Strings
((0|1)(0|1))*

Matches binary strings of even length

Example: 01, 1010, 0011
Strings Ending with 'ab'
(a|b)*ab

Matches strings ending with 'ab'

Example: aab, bab, aaab
At Least One 'a'
b*ab*|a(a|b)*

Matches strings with at least one 'a'

Example: a, ba, ab, aab

Visual Pattern Builder

Build regular expressions visually by combining components

Click buttons above to build your pattern

Enhanced RegEx Tester

Test strings with visual matching and step-by-step execution

ss="fas fa-tachometer-alt mr-2">Animation Speed: 1x
Mode:
0ms Avg Time
0 Total Tests
0% Match Rate
Low Complexity

Pattern Statistics

Pattern Length: 0
aVZ Used: 0
Groups: 0
Tests Run: 0
Matches Found: 0
Pattern Complexity
Simple pattern with basic aVZ
Quick Test Patterns
Basic Patterns
a*
Zero or more 'a'
a+
One or more 'a'
a?
Optional 'a'
(a|b)*
Any combination of a and b
Advanced Patterns
(a|b)*ab
Strings ending with 'ab'
(01|10)*
Alternating binary
[0-9]+
One or more digits
\w+@\w+\.\w+
Basic email pattern

Visual Pattern Representation

Batch Testing & Analysis

Test multiple strings and analyze pattern matching behavior

Pattern Converter & Generator

Convert between different regex formats and generate patterns

Convert to logic-gate
Pattern Generator