Regular Expressions in Java
Regular expressions (regex) are used for pattern matching in strings.
Example
import java.util.regex.*;
String text = "My phone: 123-456-7890";
Pattern pattern = Pattern.compile("\\d{3}-\\d{3}-\\d{4}");
Matcher matcher = pattern.matcher(text);
if (matcher.find()) {
System.out.println("Found: " + matcher.group());
}