regexp.md

   1 ---
   2 title: regexp
   3 category: Others
   4 layout: 2017/sheet
   5 weight: -1
   6 authors:
   7   - github: rizqyhi
   8 updated: 2019-03-24
   9 description: |
  10   Basic cheatsheets for regular expression
  11 ---
  12
  13 ##
  14
  15 {: .-three-column}
  16
  17 ### Character classes
  18
  19 | Pattern | Description                    |
  20 | ------- | ------------------------------ |
  21 | `.`     | Any character, except newline  |
  22 | `\w`    | Word                           |
  23 | `\d`    | Digit                          |
  24 | `\s`    | Whitespace                     |
  25 | `\W`    | Not word                       |
  26 | `\D`    | Not digit                      |
  27 | `\S`    | Not whitespace                 |
  28 | `[abc]` | Any of a, b, or c              |
  29 | `[a-e]` | Characters between `a` and `e` |
  30 | `[1-9]` | Digit between `1` and `9`      |
  31
  32 ### Anchors
  33
  34 | Pattern | Description      |
  35 | ------- | ---------------- |
  36 | `^abc`  | Start with `abc` |
  37 | `abc$`  | End with `abc`   |
  38
  39 ### Escaped characters
  40
  41 | Pattern    | Description                            |
  42 | ---------- | -------------------------------------- |
  43 | `\. \* \\` | Escape special character used by regex |
  44 | `\t`       | Tab                                    |
  45 | `\n`       | Newline                                |
  46 | `\r`       | Carriage return                        |
  47
  48 ### Groups
  49
  50 | Pattern | Description   |
  51 | ------- | ------------- |
  52 | `(abc)` | Capture group |
  53
  54 ### Quantifiers
  55
  56 | Pattern  | Description           |
  57 | -------- | --------------------- |
  58 | `a*`     | Match 0 or more       |
  59 | `a+`     | Match 1 or more       |
  60 | `a?`     | Match 0 or 1          |
  61 | `a{5}`   | Match exactly 5       |
  62 | `a{,3}`  | Match up to 3         |
  63 | `a{3,}`  | Match 3 or more       |
  64 | `a{1,3}` | Match between 1 and 3 |
  65