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
How to check multiple regex patterns against an input? Using Java.
The "|" meta character: The meta character "|" in Java regular expressions allows you to match more than one regular expressions for example if you need to match a particular input text with more than one expression you need to separate them using it as:
exp1|exp2|exp3
Example
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class SampleExample {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("Enter your input: ");
String input = sc.nextLine();
//Regular expression
String regex = "\d{10}|^[aeiou]";
//Creating a pattern object
Pattern pattern = Pattern.compile(regex);
//Creating a Matcher object
Matcher matcher = pattern.matcher(input);
if(matcher.find()) {
System.out.println(input+" is valid");
}else {
System.out.println(input+" is not valid");
}
}
}Output 1
Enter your input: 9848033228 9848033228 is valid
Output 2
Enter your input: an apple a day keeps doctor away an apple a day keeps doctor away is valid
Using List object
Another solution is that you compile all the regular expressions using individual Pattern objects and add them to a list object and find the match on the input text as −
List list = new ArrayList<>();
list.add(Pattern.compile(regex1));
list.add(Pattern.compile(regex2));
for (Pattern pattern: list) {
Matcher matcher = pattern.matcher(input);
if(matcher.find()) {
. . . . . . . . . . . . . . .
}else {
. . . . . . . . . . . . . . .
}
}Example
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class MultipleRegex {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("Enter your input: ");
String input = sc.nextLine();
//Regular expressions
String regex1 = "\d{10}";
String regex2 = "^[aeiou]";
//Creating a pattern objects
Pattern pattern1 = Pattern.compile(regex1);
Pattern pattern2 = Pattern.compile(regex2);
//Creating an List object
List<Pattern> patterns = new ArrayList<>();
patterns.add(pattern1);
patterns.add(pattern2);
for (Pattern pattern: patterns) {
Matcher matcher = pattern.matcher(input);
if(matcher.find()) {
System.out.println("For regex "+pattern.pattern()+" "+input+" is valid");
} else {
System.out.println("For regex "+pattern.pattern()+" "+input+" is not valid");
}
}
}
}Output 1
Enter your input:
9848033228
For regex \d{10} 9848033228 is valid
For regex ^[aeiou] 9848033228 is not validOutput 2
Enter your input:
an apple a day keeps doctor away
For regex \d{10} an apple a day keeps doctor away is not valid
For regex ^[aeiou] an apple a day keeps doctor away is valid
Updated on: 10-Jan-2020
4K+ Views
Advertisements