Regex in Java

Methods

#Pattern

Pattern compile(String regex [, int flags])
boolean matches([String regex, ] CharSequence input)
String[] split(String regex [, int limit])
String quote(String s)

#Matcher

int start([int group | String name])
int end([int group | String name])
boolean find([int start])
String group([int group | String name])
Matcher reset()

#String

boolean matches(String regex)
String replaceAll(String regex, String replacement)
String[] split(String regex[, int limit]) There are more methods …

Pattern Fields

-	-
`CANON_EQ`	Canonical equivalence
`CASE_INSENSITIVE`	Case-insensitive matching
`COMMENTS`	Permits whitespace and comments
`DOTALL`	Dotall mode
`MULTILINE`	Multiline mode
`UNICODE_CASE`	Unicode-aware case folding
`UNIX_LINES`	Unix lines mode

Styles

#First way

Pattern p = Pattern.compile(".s", Pattern.CASE_INSENSITIVE);
Matcher m = p.matcher("aS");  
boolean s1 = m.matches();  
System.out.println(s1);   // Outputs: true

#Second way

boolean s2 = Pattern.compile("[0-9]+").matcher("123").matches();  
System.out.println(s2);   // Outputs: true

#Third way

boolean s3 = Pattern.matches(".s", "XXXX");  
System.out.println(s3);   // Outputs: false

Comments