Regular Expression Novice Tutorial

1. Common meta characters

Code	Description
.	Match any character other than line break
\w	Match letters or numbers or underscores or kanji
\s	Match any of the whitespace characters
*	* The previous content can be
\d	Match numbers can be reused any number of times to make the entire expression match
\b	Match the beginning or end of a word
^	Match the start of a string
$	Match the end of a string

2. Repeat

Code \ Syntax	Description
*	Repeat 0 or more times
+	Repeat one or more times
？	Repeat 0 or one time
N	Repeat n times
{N,}	Repeat N or more times
{N,m}	Repeat N to M times

3. Escape character \

4. Character classes

square brackets [] list the characters to match, such as [Aue], matching any one of them.

Specifies a range of characters, such as [1-9],[a-za-z].

5. Branching conditions

There are several rules, as long as you match one of them. with | Separate the different rules.

6. Grouping

Repeats multiple characters. You can specify the number of repetitions of this sub-expression by wrapping it up as a subexpression.

Regular Expression Novice Tutorial