Regular Expressions


23 Topics

5 requests active popular

Getting started with Regular Expressions Introduction Topic

17
Character Guide
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edited Dec 1 '16 at 18:01
+7

Anchor Characters: Caret (^) All Versions

25
Start of Line
15
Escaping the caret character
2 more examples
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edited Jul 29 '16 at 18:05
+1

Greedy and Lazy patterns All Versions

26
Greediness versus Laziness
1
Boundaries with multiple matches
1 improvement request
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edited Sep 12 '16 at 16:55
+1

Lookahead and Lookbehind All Versions

15
Basics
6
Simulating variable-length lookbehind with \K
1 more example
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edited Dec 6 '16 at 4:50

Regex modifiers (flags) All Versions

3
VERBOSE / COMMENT / IgnorePatternWhitespace modifier
2
DOTALL modifier
9 more examples
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edited Jan 20 at 8:42

Useful Regex Showcase All Versions

5
Match an email address
3
Match a date
4 more examples
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edited Sep 12 '16 at 21:36
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Capture Groups All Versions

4
Basic Capture Groups
4
Named Capture Groups
1 more example
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edited Nov 18 '16 at 7:14

Recursion Perl5–6OnigurumaInitial–OnigmoBoost1.61.0

3
Recurse into a subpattern
2
Recursions are atomic (PCRE)
4 more examples
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edited Jul 31 '16 at 3:24

Named capture groups All Versions

5
What a named capture group looks like
3
Reference a named capture group
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created Jul 19 '16 at 2:16

Regular Expression Engine Types All Versions

5
NFA
3
DFA
1 improvement request
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edited Jan 1 at 23:37

Character classes All Versions

3
Character class and common problems faced by beginner
1
Match different, similar words
4 more examples
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edited Aug 18 '16 at 9:03
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Word Boundary All Versions

4
Word boundaries
2
Find patterns at the beginning or end of a word
2 more examples
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edited Aug 1 '16 at 2:45

Anchor Characters: Dollar ($) All Versions

7
Match a letter at the end of a line or string
-1
Matching an expression at the end of the line or string.
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edited Dec 19 '16 at 8:39

Match Reset: \K All Versions

6
Search and replace using \K operator
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edited Feb 17 at 16:13

When you should NOT use Regular Expressions All Versions

2
Parsing HTML (or XML, or JSON, or C code, or…)
2
Simple string operations
1 more example
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edited Jan 10 at 4:01

Back reference All Versions

3
Basics
2
Ambiguous Backreferences
1 improvement request
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edited Sep 11 '16 at 8:30

Escaping All Versions

2
What characters need to be escaped?
1
/Delimiters/
2 more examples
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edited Sep 11 '16 at 8:34

Backtracking All Versions

2
Why can backtracking be a trap?
1
What causes Backtracking?
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edited Oct 20 '16 at 17:29

UTF-8 matchers: Letters, Marks, Punctuation etc. All Versions

2
Matching letters in different alphabets
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created Jul 21 '16 at 19:57

Matching Simple Patterns All Versions

1
Matching leading/trailing spaces
1
Matching various numbers
3 more examples
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edited Apr 21 '16 at 7:21
1 2
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Stack Overflow Podcast #102: What Can We Learn from Uber?

Introduction Topic

 Getting started with Regular Expressions