Regular Expression Basics

1. \b Represents the beginning or end of a word. Such as: \bhi\b represents a perfect match for the Hi Word

2. * represents any character that matches except newline characters.

. * Together, any number of characters without a newline character

For example: \bhi\b.*\blucy\b represents the first a hi word followed by any character (except for newline characters), finally Lucy ends the string.

3, \d match a number (0-9 of a number)

For example: 0\d{2}-\d{8} represents 0, followed by two digit connectors-the number after a 8

4, \s match any white space symbol (Space, tab, line break, Chinese full-width space)

5. \w matches letters or numbers or underscores or kanji

6. ^ Match string start

7, $ match string end

8, \d+ match 1 or more numbers

\d* matches any number, possibly 0 digits

9, ^\d{5,12}$ represents 5-12 digits

10. Transfer characters, find special words such as * + \. When special characters are added, the front plus \

such as: unibetter\.com matching unibetter.com

C:\\Windows matching C:\Windows

11. Repetition

such as * Repeat 0 or more times

+ Repeat one more time including once

？ Repeat 0 or 1 times.

{n} repeats n times

{n,} repeats n or more times

{N,m} repeats n to M times

Regular Expression Basics