qualifiers
?
/used? / indicates that the preceding character ‘d’ appears once or zero times in the used type
The value can be used or ues
+
Matches one or more characters
Enter ab+c to match ABC, abbc, abBBC 3. * To match 0 or more characters
Type ab * c
The value can match ABC abbc abBBC AC 4. {} Specify the exact number and range of occurrences. Enter ab{6}c To specify six occurrences of characters
It can match abbbBBBC
Type ab{2,5}c b may occur between 2-6 times abBBC
Input ab{2,}c b occurs more than twice. There is no limit on the maximum number of occurrences
abbbbbbbc
The object of a qualifier is a character
Matching multiple characters
STR =’abcccabaabbab’ (ab
| | \ d or operations (qq sina) after matching a number, or digital qq, sina or Numbers
Character classes
[ABC] Find one of a or B or C where ranges can be written
The value of [^0-9] is reversed, and a character other than the digits 0-9 is taken
metacharacters
\d digit \w Alphanumeric underscore \s blank character, including TAB and newline characters \d,\ w,\ s are the opposite of the above meaning
. Represents any character but does not contain a newline character
^ A begins with a b$ends with b
Lazy match
The default is greedy matching: add as many matches as possible after the expression