Regex in Java

#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 …

#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