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

import Foundation let pattern = ##"\b(?:https?:\/\/)(?:www\d?\.)?[-\w\d&#%?\/=\.+]+\b"## let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines) let testString = #""" HEN 1 ELSE 0 END AS CONNECT_BY_ISBRANCH , CASE WHEN t.id IN (SELECT parent_id FROM tbl) THEN 0 ELSE 1 END AS CONNECT_BY_ISLEAF , CASE WHEN th.SYS_CONNECT_BY_PATH_id LIKE '%/' + CAST(t.id AS VARCHAR(MAX)) + '/%' THEN 1 ELSE 0 END AS CONNECT_BY_ISCYCLE , th.SYS_CONNECT_BY_PATH_id + CAST(t.id AS VARCHAR(MAX)) + '/' AS SYS_CONNECT_BY_PATH_id , th.SYS_CONNECT_BY_PATH_name + CAST(t.name AS VARCHAR(MAX)) + '/' AS SYS_CONNECT_BY_PATH_name , th.root_id , t.* FROM tbl t JOIN tbl_hierarchy th ON (th.id = t.parent_id) -- CONNECT BY PRIOR id = parent_id WHERE th.CONNECT_BY_ISCYCLE = 0) -- NOCYCLE SELECT th.* --, REPLICATE(' ', (th."LEVEL" - 1) * 3) + th.name AS tbl_hierarchy FROM tbl_hierarchy th JOIN tbl CONNECT_BY_ROOT ON (CONNECT_BY_ROOT.id = th.root_id) ORDER BY th.SYS_CONNECT_BY_PATH_name; -- ORDER SIBLINGS BY name هذا شرح لميزات CONNECT BY الموضّحة أعلاه: https://academy.hsoub.com/programming/sql/%D8%A7%D9%84%D8%AA%D8%B9%D8%A7%D8%A8%D9%8A%D8%B1-%D8%A7%D9%84%D8%AC%D8%AF%D9%88%D9%84%D9%8A%D8%A9-%D8%A7%D9%84%D8%B4%D8%A7%D8%A6%D8%B9%D8%A9-common-table-expressions-%D9%81%D9%8A-sql-r856/ and http://www.watheq.xyz/ and https://twitter.com/home العبارات CONNECT BY: تحدّد العلاقة التي تعرّف التشعّب START WITH: تحدّد العقدة الجذرية (root nodes). ORDER SIBLINGS BY: تحدّد ترتيب النتائج المعاملات NOCYCLE: توقِف معالجة فرع معيّن عند رصد شعبة دورية (loop). لأنّ الشعب الصالحة هي الشعب غير الدورية (Directed Acyclic)، أي الشعب التي لا يمكن العودة عبرها إلى العقدة نفسها. العمليات PRIOR: تحصل على البيانات من العقدة الأب (node's parent). CONNECT_BY_ROOT: تحصل على البيانات من العقدة الجذرية. أشباه الأعمدة Pseudocolumns LEVEL: تشير إلى مسافة العقدة من جذرها. CONNECT_BY_ISLEAF: تشير إلى عقدة بدون فروعها. CONNECT_BY_ISCYCLE: تشير إلى عقدة ذات مرجع دائري (circular reference). الدوال SYS_CONNECT_BY_PATH: تعيد سلسلة نصية تمثّل المسار من الجذر إلى العقدة. ترجمة -وبتصرّف- للفصل 46 من الكتاب SQL Notes for Professionals """# let stringRange = NSRange(location: 0, length: testString.utf16.count) let matches = regex.matches(in: testString, range: stringRange) var result: [[String]] = [] for match in matches { var groups: [String] = [] for rangeIndex in 1 ..< match.numberOfRanges { let nsRange = match.range(at: rangeIndex) guard !NSEqualRanges(nsRange, NSMakeRange(NSNotFound, 0)) else { continue } let string = (testString as NSString).substring(with: nsRange) groups.append(string) } if !groups.isEmpty { result.append(groups) } } print(result)

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 Swift 5.2, please visit: https://developer.apple.com/documentation/foundation/nsregularexpression