Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
A Reluctant qualifier in Java Regular Expressions
The reluctant qualifier starts with the shortest string size as possible. If a match is found by the engine, the process continues to find more matches otherwise the engine adds a character to the searched string section and tries again. This continues until a match is obtained or the string is used up.
The regex "B+?" is used to find the match in the string "SkyIsBlue".
A program that demonstrates this is given as follows:
Example
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Demo {
public static void main(String args[]) {
String regex = "B+?";
String str = "SkyIsBlue";
Pattern p = Pattern.compile(regex);
Matcher m = p.matcher(str);
while (m.find()) {
System.out.println("Match String starts at index: " + m.start());
}
}
}Output
Match String starts at index: 5
Now let us understand the above program.
The regex is “B+?”. This is searched in the string sequence "SkyIsBlue". The find() method is used to find if the regex is in the input sequence and its index is printed. A code snippet which demonstrates this is as follows:
String regex = "B+?";
String str = "SkyIsBlue";
Pattern p = Pattern.compile(regex);
Matcher m = p.matcher(str);
while(m.find()) {
System.out.println("Match String starts at index: " + m.start());
}
Updated on: 30-Jul-2019
93 Views
Advertisements