trycapturinggroups.java

nanjing university cs 的java课件。 对新手很有用。付课件中源码。

import java.util.regex.Matcher;
import java.util.regex.Pattern;

class TryCapturingGroups{
	public static void main(String[] args){
		String regEx = "[+|-]?(\\d+(\\.\\d*)?)|(\\.\\d+)";
		//String regEx = "[+|-]?((\\d+(\\.\\d*)?)|(\\.\\d+))";
		String str = "256 is the square of 16 and -2.5 squared is 6.25 "
			+ "and -.243 is less than 0.12345.";
		
		Pattern pattern = Pattern.compile(regEx);
		Matcher m = pattern.matcher(str);
		
		while(m.find()){
			for(int i = 0; i <= m.groupCount(); i++)
				System.out.println("Group " + i + ": " + m.group(i));
		}
	}
}