Ruby Regular Expressions
A regular expression is a special sequence of characters that helps you match or find other strings or sets of strings using a specialized syntax held in a pattern. A regular expression literal is a pattern between slashes or between arbitrary delimiters followed by %r as follows: Syntax: /pattern//pattern/im # option can be specified%r!/usr/local! # general delimited regular expression Example: #! This will produce the following result: Line1 contains Cats Regular-expression modifiers: Regular expression literals may include an optional modifier to control various aspects of matching. Like string literals delimited with %Q, Ruby allows you to begin your regular expressions with %r followed by a delimiter of your choice. # Following matches a single slash character, no escape required%r|/| # Flag characters are allowed with this syntax, too%r[</(.*)>]i Regular-expression patterns: Except for control characters, (+ ? Following table lists the regular expression syntax that is available in Ruby. #!
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