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

/
/
g

Test String

Code Generator

Language

Generated Code

$re = '/[HDQhdq]2\d{8}/'; $str = '# 配對身分證字號，用台灣縣市與男女做範例 # 題目說明區塊 請幫我找出桃園縣(H), 台南市(D), 嘉義縣(Q)中為女生的身分證字號 #欲測試資料集 A121040176 L186856359 Z127598010 I114537095 D279884447 L186834359 D243736345 I114537095 Q146110887 D187217314 I114537095 Q243556025 Z127598010 H250077453 Q188367037 # 應配對結果(亮色區塊) D279884447 D243736345 Q243556025 H250077453 # (選項)寫上註解，好好說明你怎麼想的 就直覺想到就這樣寫了＠＠ # (選項)將你的 Regex 註解起來，使用 Extended Formating / [HDQhdq] # Match 可能為HDQhdq中任一個字元 2 # Match 數字 2 \\d{8} # Match 任意數字長度限定為8 / '; preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0); // Print the entire match result var_dump($matches);

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 PHP, please visit: http://php.net/manual/en/ref.pcre.php