How to use java regular expressions

Usage: 1. Create a java sample file; 2. Find "test" in the input string "This is a test string"; 3. Use the Pattern.compile() method to compile the regular expression , and then use the Matcher class to process the match; 4. The m.find() method is used to check whether there is a match. If there is a match, m.group(0) will return the matching string.

Operating system for this tutorial: Windows 10 system, Dell G3 computer.

In Java, you can use regular expressions using the Pattern and Matcher classes. The following is a simple example:

java

##

import java.util.regex.Pattern;  
import java.util.regex.Matcher;  
  
public class Main {  
    public static void main(String[] args) {  
        String input = "This is a test string";  
        String pattern = "test";  
  
        Pattern r = Pattern.compile(pattern);  
        Matcher m = r.matcher(input);  
        if (m.find()) {  
            System.out.println("Found value: " + m.group(0));  
        } else {  
            System.out.println("NO MATCH");  
        }  
    }  
}

In this example, we Trying to find "test" in the input string "This is a test string". We use the Pattern.compile() method to compile the regular expression and then use the Matcher class to handle the matching. The m.find() method is used to check whether there is a match. If there is a match, m.group(0) will return the matching string.

Note that this is just a simple example. In actual use, you may need to deal with more complex regular expressions and more complex matching logic.

The above is the detailed content of How to use java regular expressions. For more information, please follow other related articles on the PHP Chinese website!