I have the following piece of code:
String range = "(15-42)";
String regexp = "(\\d{1,})(\\d{1,})";
Pattern p = Pattern.compile(regexp);
Matcher m = p.matcher(range);
m.find();
System.out.println(m.groupCount());
for(int i=0; i<=m.groupCount(); i++){
System.out.println("value:" + m.group());
}
And then I have the following output:
2
value: 15
value: 1
value: 5
But I'm only expecting to see 2 values: 15 and 42.
Why doesn't this work as expected?
You need to add hyphen to the regex and use .group(i) and start with index 1 (because m.group(0) is the whole match value that you do not need):
String range = "(15-42)";
String regexp = "(\\d{1,})-(\\d{1,})";
Pattern p = Pattern.compile(regexp);
Matcher m = p.matcher(range);
if (m.find()) {
System.out.println(m.groupCount());
for(int i=1; i<=m.groupCount(); i++){
System.out.println("value:" + m.group(i));
}
}
See IDEONE demo
Now, you will have
2 // This is the number of capturing groups
value:15 // This is the value of the first capturing group
value:42 // This is the value of the second capturing group
{1,} limiting quantifier is semantically equal to + quantifier (1 or more), so you can use String regexp = "(\\d+)-(\\d+)";The mistake is that you are always calling m.group() when you should be calling m.group(i).
The other mistake is that you forgot the hyphen in your regex.
Working code:
String range = "(15-42)";
String regexp = "(\\d{1,})-(\\d{1,})";
Pattern p = Pattern.compile(regexp);
Matcher m = p.matcher(range);
m.find();
for (int i = 0; i <= m.groupCount(); i++) {
System.out.println("value:" + m.group(i));
}
This prints the expected:
value:15-42
value:15
value:42
m.group(i). But I don't want to argue here, I can delete my answer if you want.Its a different method but you can use this solution
System.out.println(m.groupCount());
String[] value = m.group().split("-");
for(int i=0; i<value.length; i++){
System.out.println("value:" + value[i]);
}
String regexp = "(\\d{1,})-(\\d{1,})";. See ideone.com/JeNO2u