Question

I have a string line like the following :

A:B:C:D:E:F:G:H:I:J:K:L:M

It means delimiter ( : ) count is 12 . This line is valid.

Now suppose you have a following line :

A:B:C:D:E:F:G:H:::::

This line is also valid because it contains 12 delimiter . where 8 values are present and 4 values are blank.

Now the following line should be invalid :

A:B:C:D:E:F: — Invalid – because it contains only 6 values but expected are 12.

how to do this .. ? I tried the following code , but not getting the desired output :

String strLine = "A:B:C:D:E:F:G:H:::::" ;
int delimiterCount = 12 ; 

String[] ValuesArray = strLine.split(":");
 if(ValuesArray.length != delimiterCounter){
 System.out.println(Invalid);
 }else {
 System.out.println("ValidLine");
 }

I am getting the output as Invalid where as it sould be Valid.

Answer 1

If you want to use split, and it’s not a bad approach really (although it might be for this particular situation), you need to pass -1 as the second argument to split otherwise it removes empty strings.

See http://ideone.com/gaUw5.

It is good to know this about split. Some languages require the -1 and some do not.

The code

class Main {
    public static void main(String[] args) {
        String line = "A:B:C:D:E:F:G:H:::::" ;
        int delimiterCount = 12 ; 

        String[] values = line.split(":", -1);
        if (values.length != delimiterCount + 1) {
            System.out.println("Invalid Line");
        } else {
            System.out.println("Valid Line");
        }
    }
}