learning java regular expressions

        var regStr = "Java is very good";
        Matcher m  = Pattern.compile("\\w+").matcher(regStr);
        while(m.find()){
            System.out.println(m.group() + " start:" + m.start() + ",end:" + m.end());
        }

output:

Java start:0,end:4
is start:5,end:7
very start:8,end:12
good start:13,end:17