Hi,
I have a string with something like
"123/45ABC888"
There are 4 parts:
"123" , "/45", "ABC", and "888",
the first part contains only numbers,
the second part contains only numbers too but starting with a "/",
the third part contains only letters,
the fourth part contains only numbers.
How to fetch the parts from a string?
Regards,
Pengyou
If you have varying length of each of the 4parts and are guarenteed that each part will have at least 1 member then you can easily do a state machine. The algo goes like this:
State 1 read numeric digits until "/" throw away the "/"
State 2 read read numbers until next is a letter
State 3 read letters until next is a number
State 4 read the rest
If you don't mind a little black magic... public class Test
{
public static void main(String... args)
{
String str = "123/45ABC888";
String[] parts = str.split("(?<=\\d)(?=\\D)|(?<=[A-Z])(?=[^A-Z])");
for (String s : parts)
{
System.out.printf("[%s]%n", s);
}
}
}
^_^
I tried:
public class Test
{
public static void main(String[] args)
{
String str = "123/45ABC888";
String[] parts = str.split("(?<=\\d)(?=\\D)|(?<=[A-Z])(?=[^A-Z])");
System.out.println("parts.length="+parts.length);
for (int i=0;i<parts.length;i++ ){
System.out.println("parts["+i+"]="+parts);
}
}
}
It gave:
parts[0]=123
parts[1]=123
parts[2]=123
parts[3]=123
But I would have
parts.length=4
parts[0]=123
parts[1]=45
parts[2]=ABC
parts[3]=888
Could any regular expression guru help?
Pengyou">
Your (or uncle_alice's) code produces the following output:
parts.length=4
parts[0]=123
parts[1]=/45
parts[2]=ABC
parts[3]=888
You could do it like this:
String text = "123/45ABC888";
Pattern pattern = Pattern.compile("\\d+|[a-zA-Z]+");
Matcher matcher = pattern.matcher(text);
while (matcher.find()) {
System.out.println(matcher.group());
}
That way you won't have the "/" in your substrings.
Oh, so you don't want the slash! Then add it to the regex: String[] parts = str.split("/|(?<=\\d)(?=\\D)|(?<=[A-Z])(?=[^A-Z])");
And if you change the requirements any more, you should go with a positive-matching approach (like what prometheuzz suggested) instead of split(). The regexes tend to be much simpler that way.
Also, please use [code][/code] tags when you post source code.
with
String text = "123ABC888";
Pattern pattern = Pattern.compile("\\d+|[a-zA-Z]+");
Matcher matcher = pattern.matcher(text);
while (matcher.find()) {
System.out.println(matcher.group());
}
I will get as result
For "123ABC888"
123
ABC
888
For "123/44ABC888"
123
44
ABC
888
It is fine. But I want to have always 4 parts:
Part 1: number
Part 2: number, separated by "/"
Part 3: letter
Part 4: number
Part 2 is optional. Part 3 and Part 4 together are also optional.
So when I get for "123ABC", 123 and ABC, how can I know that "ABC" is part 3 but not part 2.
Any idea for this?
Pengyou
> with
>
> String text = "123ABC888";
> Pattern pattern =
> Pattern.compile("\\d+|[a-zA-Z]+");
>Matcher matcher = pattern.matcher(text);
> while (matcher.find()) {
>System.out.println(matcher.group());
>
>
> I will get as result
>
> For "123ABC888"
> 123
> ABC
> 888
>
> For "123/44ABC888"
> 123
> 44
> ABC
> 888
>
> It is fine. But I want to have always 4 parts:
> Part 1: number
> Part 2: number, separated by "/"
> Part 3: letter
> Part 4: number
>
> Part 2 is optional. Part 3 and Part 4 together are
> also optional.
>
> So when I get for "123ABC", 123 and ABC, how can I
> know that "ABC" is part 3 but not part 2.
>
> Any idea for this?
>
> Pengyou
Finally I solved my problem by
if (text.indexOf("/")>0)
This allows me to know if part 2 is there.
