Regular Expressions: Introduction to regex, common patterns, and practical use cases in Java
Regular Expressions (regex) are powerful tools for pattern matching in strings. In Java, regex is supported through the java.util.regex package. Let's dive into the basics of regex in Java.
Common Patterns
Here are some common regex patterns:
\d: Matches a digit\w: Matches a word character\s: Matches a whitespace character
Sample Examples
Let's see some examples:
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RegexExample {
public static void main(String[] args) {
String text = "Hello, 123 World!";
String pattern = "\\d+";
Pattern p = Pattern.compile(pattern);
Matcher m = p.matcher(text);
while (m.find()) {
System.out.println("Found: " + m.group());
}
}
}
Output:
Found: 123
Practical Use Cases
Regex can be used for various practical applications such as:
- Form validation
- Data extraction
- Search and replace operations
Importance in Interviews
Regex is a common topic in technical interviews, especially for software development roles. Understanding regex can help you solve complex string manipulation problems efficiently.
Conclusion
Regular Expressions are a powerful tool for pattern matching in Java. By mastering regex, you can improve your string manipulation skills and tackle a wide range of tasks efficiently.
