Reg expression matching issue

Tim Smith

On 2007-12-06, Knute Johnson <nospam@rabbitbrush.frazmtn.com> wrote:
>> but it shouldn't match the following:
>>
>> asdjkas hdjasdhsajkd
>> 7674367346
>> 33
>> asdjkas 343
....
> import java.util.regex.*;
>
> public class test2 {
> public static void main(String[] args) {
> String str = ";alsdlkajsdf 32344 lkls3 3323 llsdfsdf";
> Pattern p = Pattern.compile(".*\\d{5}.*");
> Matcher m = p.matcher(str);
>
> System.out.println(m.matches());
> }
> }

Nope. That will match strings that contain runs of 5 or more digits.
He wants runs of exactly 5 digits.

Tim Smith

On 2007-12-06, Knute Johnson <nospam@rabbitbrush.frazmtn.com> wrote:
>> but it shouldn't match the following:
>>
>> asdjkas hdjasdhsajkd
>> 7674367346
>> 33
>> asdjkas 343
....
> import java.util.regex.*;
>
> public class test2 {
> public static void main(String[] args) {
> String str = ";alsdlkajsdf 32344 lkls3 3323 llsdfsdf";
> Pattern p = Pattern.compile(".*\\d{5}.*");
> Matcher m = p.matcher(str);
>
> System.out.println(m.matches());
> }
> }

Nope. That will match strings that contain runs of 5 or more digits.
He wants runs of exactly 5 digits.

Tim Smith

On 2007-12-06, Knute Johnson <nospam@rabbitbrush.frazmtn.com> wrote:
> Pattern p = Pattern.compile(".*\\d{5}.*");
> Matcher m = p.matcher(str);

Here's a way to fix that so it won't incorrectly match "foo123456bar"
and similar strings:

Pattern p = Pattern.compile(".*[^0-9]\\d{5}[^0-9].*");
Matcher m = p.matcher("a"+str+"a");

The "a"+str+"a" ensures that we do not have to worry about the special
cases of the 5 digits being the first or last digits of the string, and
the change to the regular expression ensures that the 5 digits are a run
of exactly 5 digits, by requiring that they be bordered by a non-digit.

Tim Smith

On 2007-12-06, Knute Johnson <nospam@rabbitbrush.frazmtn.com> wrote:
> Pattern p = Pattern.compile(".*\\d{5}.*");
> Matcher m = p.matcher(str);

Here's a way to fix that so it won't incorrectly match "foo123456bar"
and similar strings:

Pattern p = Pattern.compile(".*[^0-9]\\d{5}[^0-9].*");
Matcher m = p.matcher("a"+str+"a");

The "a"+str+"a" ensures that we do not have to worry about the special
cases of the 5 digits being the first or last digits of the string, and
the change to the regular expression ensures that the 5 digits are a run
of exactly 5 digits, by requiring that they be bordered by a non-digit.

Tim Smith

On 2007-12-06, Knute Johnson <nospam@rabbitbrush.frazmtn.com> wrote:
>> but it shouldn't match the following:
>>
>> asdjkas hdjasdhsajkd
>> 7674367346
>> 33
>> asdjkas 343
....
> import java.util.regex.*;
>
> public class test2 {
> public static void main(String[] args) {
> String str = ";alsdlkajsdf 32344 lkls3 3323 llsdfsdf";
> Pattern p = Pattern.compile(".*\\d{5}.*");
> Matcher m = p.matcher(str);
>
> System.out.println(m.matches());
> }
> }

Nope. That will match strings that contain runs of 5 or more digits.
He wants runs of exactly 5 digits.

Tim Smith

On 2007-12-06, Knute Johnson <nospam@rabbitbrush.frazmtn.com> wrote:
> Pattern p = Pattern.compile(".*\\d{5}.*");
> Matcher m = p.matcher(str);

Here's a way to fix that so it won't incorrectly match "foo123456bar"
and similar strings:

Pattern p = Pattern.compile(".*[^0-9]\\d{5}[^0-9].*");
Matcher m = p.matcher("a"+str+"a");

The "a"+str+"a" ensures that we do not have to worry about the special
cases of the 5 digits being the first or last digits of the string, and
the change to the regular expression ensures that the 5 digits are a run
of exactly 5 digits, by requiring that they be bordered by a non-digit.

Tim Smith

On 2007-12-06, Knute Johnson <nospam@rabbitbrush.frazmtn.com> wrote:
>> but it shouldn't match the following:
>>
>> asdjkas hdjasdhsajkd
>> 7674367346
>> 33
>> asdjkas 343
....
> import java.util.regex.*;
>
> public class test2 {
> public static void main(String[] args) {
> String str = ";alsdlkajsdf 32344 lkls3 3323 llsdfsdf";
> Pattern p = Pattern.compile(".*\\d{5}.*");
> Matcher m = p.matcher(str);
>
> System.out.println(m.matches());
> }
> }

Nope. That will match strings that contain runs of 5 or more digits.
He wants runs of exactly 5 digits.

Tim Smith

On 2007-12-06, Knute Johnson <nospam@rabbitbrush.frazmtn.com> wrote:
> Pattern p = Pattern.compile(".*\\d{5}.*");
> Matcher m = p.matcher(str);

Here's a way to fix that so it won't incorrectly match "foo123456bar"
and similar strings:

Pattern p = Pattern.compile(".*[^0-9]\\d{5}[^0-9].*");
Matcher m = p.matcher("a"+str+"a");

The "a"+str+"a" ensures that we do not have to worry about the special
cases of the 5 digits being the first or last digits of the string, and
the change to the regular expression ensures that the 5 digits are a run
of exactly 5 digits, by requiring that they be bordered by a non-digit.

Tim Smith

On 2007-12-06, Knute Johnson <nospam@rabbitbrush.frazmtn.com> wrote:
>> but it shouldn't match the following:
>>
>> asdjkas hdjasdhsajkd
>> 7674367346
>> 33
>> asdjkas 343
....
> import java.util.regex.*;
>
> public class test2 {
> public static void main(String[] args) {
> String str = ";alsdlkajsdf 32344 lkls3 3323 llsdfsdf";
> Pattern p = Pattern.compile(".*\\d{5}.*");
> Matcher m = p.matcher(str);
>
> System.out.println(m.matches());
> }
> }

Nope. That will match strings that contain runs of 5 or more digits.
He wants runs of exactly 5 digits.

Tim Smith

On 2007-12-06, Knute Johnson <nospam@rabbitbrush.frazmtn.com> wrote:
> Pattern p = Pattern.compile(".*\\d{5}.*");
> Matcher m = p.matcher(str);

Here's a way to fix that so it won't incorrectly match "foo123456bar"
and similar strings:

Pattern p = Pattern.compile(".*[^0-9]\\d{5}[^0-9].*");
Matcher m = p.matcher("a"+str+"a");

The "a"+str+"a" ensures that we do not have to worry about the special
cases of the 5 digits being the first or last digits of the string, and
the change to the regular expression ensures that the 5 digits are a run
of exactly 5 digits, by requiring that they be bordered by a non-digit.