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Regular Expressions

Regular Expressions are really a language in themselves. If you read any code online you will see them everywhere. So in this light it is best to get familiar with them and the most common patterns. I am hoping to develop my own little library of expressions over the next few years. I hope this page will be of use to you.

Introduction




Boundaries




Alternation


  (a|b)        a or b

Groups and Subpatters


  (...)        Anything between (brackets) is a group
  (?..)        Passive (non-c­apt­uring) group
  n           Group / Sub­pattern number "­n"

Backreferences




Character Classes & Ranges


  [rst]        r or s or t
  [^rst]       NOT r or s or t
  [a-z]        Lower case letter from a to z
  [A-Z]        Upper case letter from A to Z
  [0-9]        Digit from 0 to 9

Unicode




Quantifiers




Lookaround




Sites About Regexp & Engines



http://thevikidtruth.com/5000/?regularexpressions

08dec16   admin