I encountered a problem at http://regexone.com/example/6? You can view the problem by clicking the link. There was required a regular expression to extract the method name, filename and the line number from a particular stack trace in an android development application.

I used the following regular expression to solve the problem :

at widget.List.([a-zA-Z]+).([A-Za-z]+\.java).(\d{3,4}).

The expression works for the problem but i don't think its the correct regular expression as there is no hat(^) and dollar ($) included in it.


closed as unclear what you're asking by Jamal Aug 9 '15 at 20:27

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  • \$\begingroup\$ If you want to actually solve the problem rather than merely pass the test cases then you also need to take into account that packages can contain multiple components separated by a dot, that all names can begin with an underscore and can contain digits except at the first character, etc. \$\endgroup\$ – Peter Taylor Mar 5 '13 at 11:50
  • \$\begingroup\$ You are falsely assuming a regex should contain ^ and $. \$\endgroup\$ – Eric Mar 5 '13 at 15:35

If you wish to include the hat ^ and dollar $ signs, then the regex can be rewritten as:

^.*\s+at widget\.List\.(\w+)\((\w+\.java)\:(\d+)\)$

Ofcourse, you can still use \d{3,4} instead of \d+ but that'll result in you missing the errors in line numbers less than 100(like 1 to 99).

Similarly, you can use \w+ in place of [a-zA-Z]+ or simply, [A-z]+ will work too.

  • \$\begingroup\$ Thats a perfect regular expression built by you @Back in a Flash. Good one ! \$\endgroup\$ – newDevGuy Mar 5 '13 at 11:59

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