regex question

[John Eric Hamacher]

Hello:

My requirement for a string of characters: May contain any letter, spaces, dashes or single quotes but you cannot have two consecutive spaces, two consecutive dashes or two consecutive single quotes.

I first tried to see if I could prevent just consecutive spaces. I figured this would be the correct regex:

^[a-zA-Z\-\s'-[\s{2}]]+$

or

^[a-zA-Z\\-\\s'^[\\s{2}]]+$

or

^[a-zA-Z\\-\\s'[^\\s{2}]]+$

but I haven't come up with the solution. What would be the correct regex?

Thanks.

[Ireneusz Kordal]

Hi,

try this pattern:

    public static void main(String a[]) throws Exception {
       String [] test = { "l , - , cl\"kj " ,
                          "abc  abc",
                          "abc--abc",
                          ",,abc-abc",
                          "",
                          "abc-abc\"\"",
                          "ab-- c-a  bc\"\"",
                        };

       for( String s : test ){
           System.out.format("%-20s %b\n",
                   s,
                   s.matches("^(?!.*([\\-\",\\s])\\1)[a-zA-Z\\s\\-,\"]+$")
           );
       }
    }

Output from this program:

run:
l , - , cl"kj        true
abc  abc             false
abc--abc             false
,,abc-abc            false
                     false
abc-abc""            false
ab-- c-a  bc""       false

Edit:
Sorry, the above pattern matches double quotes instead of single quotes,
correct pattern should be:
s.matches("^(?!.*([\\-\',\\s])\\1)[a-zA-Z\\s\\-,\']+$")

[John Eric Hamacher]

Thanks! I'm going to study it to see how it works.

[John Eric Hamacher]

Wait it's allowing numbers to be present

"d - '4s" is passing though but it shouldn't

[John Eric Hamacher]

Sorry, my mistake