This is an example of how to use a regular expression match group. Using a regular expression to group matches of a String with a pattern implies that you should:
- Compile a String regular expression to a Pattern, using
compile(String regex)API method of Pattern. - Use
matcher(CharSequence input)API method of Pattern to create a Matcher that will match the given String input against this pattern. - Use
find()API method of Matcher to get the matches of the input with the pattern. - Use
group(int group)API method to get the input subsequence captured by the given group during the previous match operation.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* REmatch -- demonstrate RE Match -> group()
*
*/
public class MatchGroup {
public static void main(String[] argv) {
String pattern = "Q[^u]\d+\.";
Pattern reg = Pattern.compile(pattern);
String str = "Order QT300. Now!";
Matcher matcher = reg.matcher(str);
if (matcher.find()) {
System.out.println(pattern + " matches "" + matcher.group(0) + "" in ""
+ str + """);
} else {
System.out.println("NO MATCH");
}
}
}
Output:
Q[^u]d+. matches "QT300." in "Order QT300. Now!"
This was an example of how to use a regular expression match group in Java.
