Java Reference
In-Depth Information
pattern.ignoreCase = false // this won't work
<< false
pattern.ignoreCase // has it changed?
<< true
The only way to change the
ignoreCase
property to
false
is to redefine the regular
expression:
pattern = /java/
Special Characters
In a regular expression, there are a number of characters that have a special meaning, com-
monly known as
metacharacters
:
•
.
matches any character
•
\w
matches any word character, and is equivalent to
[A-Za-z0-9_]
•
\W
matches any non-word character, and is equivalent to [^A-Za-z0-9_]
•
\d
matches any digit character, and is equivalent to
[0-9]
•
\D
matches any non-digit character, and is equivalent to
[^0-9]
•
\s
matches any whitespace character, and is equivalent to
[ \t\r\n\f]
•
\S
matches any non-whitespace character, and is equivalent to
[^ \t\r\n\f]
Modifiers
Modifiers can be placed after a pattern to match multiple occurrences of that pattern:
•
?
matches zero or one occurrence of the pattern
•
*
matches zero or more occurrences of the pattern
