Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

~
~
gm

Test String

Code Generator

Language

Generated Code

re = /(?:(?i)WHERE|AND|OR) \(?([a-zA-Z0-9]+)/m str = ' return all strings (a-zA-Z0-9) of any length that start right after one of the following expressions: "WHERE ", "AND ", "OR ", "WHERE (", "AND (", "OR (" and end right before one of the following expressions: "=", ">", "<", "LIKE", "NOT") all these expressions should be case-insensitive. I was playing around with the following online regex-tester: https://www.phpliveregex.com/#tab-preg-match-all. However, the closest I got was this, as I dont know how to get multiple matches: preg_match_all(\'/^[where|and|or|\\(]* ([a-zA-Z0-1]*)[ |=|<|<=|>|>=|or|in]*.*$/\', $input_lines, $output_array); Some example SQL-queries: SHOULD RETURN WHERE var1=1 AND var2=1 => var1; var2 WHERE var2 IN (1, 2, 3) OR var3=2 => var2; var3 WHERE (var4 like \'%test%\' and var5 NOT LIKE \'%test%\') => var4; var5 WHERE var6 = \'test\' AnD var7=\'test2\' => var6; var7' # Print the match result str.scan(re) do |match| puts match.to_s end

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html