References
需要转义的特殊字符：
* . ? + $ ^ [ ] ( ) { } | \ /
Tutorials
Lesson 1 The 123s
\d any single digit character
\D any single non-digit character
Lesson 2: The Dot
. any single character
\. period
Lesson 3: Matching specific characters
[abc] only a, b, c single character
Lesson 4: Excluding specific characters
[^abc] not a, b or c
Lesson 5: Character ranges
[a-z] characters a to z
[0-9] number 0 to 9
\w 字母，数字，下划线。等价于[A-Za-z0-9_]
\W 等价于\[^A-Za-z0-9_]
Lesson 6: Catching some zzz’s
{m} m repetitions
{m, n} m to n repetitions
Examples:
w{3} (three w)
[wxy]{5} (five characters, each of which can be a w, x, or y)
Lesson 7: Mr. Kleene, Mr. Kleene
* zero or more repetitions *前的字符可以重复0次或者更多次
+ one or more repetitions +前的字符可以重复1次或者更多次
Match aaaabcc
Match aabbbbc
Match aacc
Skip a
answer: aa+b*c+
Lesson 8: Characters optional
? optional character ?前的字符可以出现0次或者1次
ab?c will match either the strings “abc” or “ac”
Lesson 9: All this whitespace
\s 代替any whitespace 包括space, tab(\t), new line(\n), return(\r)
\S 相反
Lesson 10: Starting and ending
^...$ starts and ends
^Mission: successful$ 文本必须以Mission: 开头, successful结尾
Lesson 11: Match groups
(...) capture group
(a(bc)) capture sub-group
(.*) capture all
Lesson 14: It’s all conditional
(abc|def) matches abc or def
Problems
Problem 1: Matching a decimal numbers
| Task | Text |
|---|---|
| Match | 3.14529 |
| Match | -255.34 |
| Match | 128 |
| Match | 1.9e10 |
| Match | 123,340.00 |
| Skip | 720p |
answer:^-?\d+(,\d+)*(\.\d+(e\d+)?)?$
Problem 2: Matching phone numbers
后面还有很多problems