Need regex for a string having characters followed by even number of digits












-1














Can anyone tell how I can write regex for a string that take one or more alphanumeric character followed by an even number of digits?



Valid:



a11a1121
bbbb11a1121


Invalid:



a11a1


I have tried ^[a-zA-Z*20-9]*$ but it is always giving true.



Can you please help in this regard?










share|improve this question




















  • 2




    Possible duplicate of Learning Regular Expressions
    – Biffen
    Nov 12 at 11:52
















-1














Can anyone tell how I can write regex for a string that take one or more alphanumeric character followed by an even number of digits?



Valid:



a11a1121
bbbb11a1121


Invalid:



a11a1


I have tried ^[a-zA-Z*20-9]*$ but it is always giving true.



Can you please help in this regard?










share|improve this question




















  • 2




    Possible duplicate of Learning Regular Expressions
    – Biffen
    Nov 12 at 11:52














-1












-1








-1







Can anyone tell how I can write regex for a string that take one or more alphanumeric character followed by an even number of digits?



Valid:



a11a1121
bbbb11a1121


Invalid:



a11a1


I have tried ^[a-zA-Z*20-9]*$ but it is always giving true.



Can you please help in this regard?










share|improve this question















Can anyone tell how I can write regex for a string that take one or more alphanumeric character followed by an even number of digits?



Valid:



a11a1121
bbbb11a1121


Invalid:



a11a1


I have tried ^[a-zA-Z*20-9]*$ but it is always giving true.



Can you please help in this regard?







java regex






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share|improve this question













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share|improve this question








edited Nov 12 at 11:53









Biffen

4,16352129




4,16352129










asked Nov 12 at 11:47









Icche Guri

96211130




96211130








  • 2




    Possible duplicate of Learning Regular Expressions
    – Biffen
    Nov 12 at 11:52














  • 2




    Possible duplicate of Learning Regular Expressions
    – Biffen
    Nov 12 at 11:52








2




2




Possible duplicate of Learning Regular Expressions
– Biffen
Nov 12 at 11:52




Possible duplicate of Learning Regular Expressions
– Biffen
Nov 12 at 11:52












2 Answers
2






active

oldest

votes


















1














The regex that you have mentioned will search for any number of [either a-z, or A-Z or 2 or 0-9]



You can break down your requirement to groups and then handle it accordingly.



Like you require at least one character. so you start with ^([a-zA-Z]+)$



Then you need numbers in the multiple of 2. so you add ^([a-zA-Z]+(dd)+)$



Now you need any number of combination of these. So the exp becomes: ^([a-zA-Z]+(dd)+)*$



You can use online tools like regex101 for these purpose. The provided regex in action here






share|improve this answer





























    1














    You can achieve it with this regexp: ^[a-z0-9]*[a-z]+([0-9]{2})*$



    Explanation :





    • [a-z0-9]*[a-z]+: a string of at least one character terminated by a non digit one


    • ([0-9]{2})*: an odd sequence of digits (0 or 2*n digits). If the even sequence cannot be null, use ([0-9]{2})+ instead.






    share|improve this answer























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      2 Answers
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      2 Answers
      2






      active

      oldest

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      active

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      active

      oldest

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      1














      The regex that you have mentioned will search for any number of [either a-z, or A-Z or 2 or 0-9]



      You can break down your requirement to groups and then handle it accordingly.



      Like you require at least one character. so you start with ^([a-zA-Z]+)$



      Then you need numbers in the multiple of 2. so you add ^([a-zA-Z]+(dd)+)$



      Now you need any number of combination of these. So the exp becomes: ^([a-zA-Z]+(dd)+)*$



      You can use online tools like regex101 for these purpose. The provided regex in action here






      share|improve this answer


























        1














        The regex that you have mentioned will search for any number of [either a-z, or A-Z or 2 or 0-9]



        You can break down your requirement to groups and then handle it accordingly.



        Like you require at least one character. so you start with ^([a-zA-Z]+)$



        Then you need numbers in the multiple of 2. so you add ^([a-zA-Z]+(dd)+)$



        Now you need any number of combination of these. So the exp becomes: ^([a-zA-Z]+(dd)+)*$



        You can use online tools like regex101 for these purpose. The provided regex in action here






        share|improve this answer
























          1












          1








          1






          The regex that you have mentioned will search for any number of [either a-z, or A-Z or 2 or 0-9]



          You can break down your requirement to groups and then handle it accordingly.



          Like you require at least one character. so you start with ^([a-zA-Z]+)$



          Then you need numbers in the multiple of 2. so you add ^([a-zA-Z]+(dd)+)$



          Now you need any number of combination of these. So the exp becomes: ^([a-zA-Z]+(dd)+)*$



          You can use online tools like regex101 for these purpose. The provided regex in action here






          share|improve this answer












          The regex that you have mentioned will search for any number of [either a-z, or A-Z or 2 or 0-9]



          You can break down your requirement to groups and then handle it accordingly.



          Like you require at least one character. so you start with ^([a-zA-Z]+)$



          Then you need numbers in the multiple of 2. so you add ^([a-zA-Z]+(dd)+)$



          Now you need any number of combination of these. So the exp becomes: ^([a-zA-Z]+(dd)+)*$



          You can use online tools like regex101 for these purpose. The provided regex in action here







          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered Nov 12 at 12:01









          suvartheec

          1,121917




          1,121917

























              1














              You can achieve it with this regexp: ^[a-z0-9]*[a-z]+([0-9]{2})*$



              Explanation :





              • [a-z0-9]*[a-z]+: a string of at least one character terminated by a non digit one


              • ([0-9]{2})*: an odd sequence of digits (0 or 2*n digits). If the even sequence cannot be null, use ([0-9]{2})+ instead.






              share|improve this answer




























                1














                You can achieve it with this regexp: ^[a-z0-9]*[a-z]+([0-9]{2})*$



                Explanation :





                • [a-z0-9]*[a-z]+: a string of at least one character terminated by a non digit one


                • ([0-9]{2})*: an odd sequence of digits (0 or 2*n digits). If the even sequence cannot be null, use ([0-9]{2})+ instead.






                share|improve this answer


























                  1












                  1








                  1






                  You can achieve it with this regexp: ^[a-z0-9]*[a-z]+([0-9]{2})*$



                  Explanation :





                  • [a-z0-9]*[a-z]+: a string of at least one character terminated by a non digit one


                  • ([0-9]{2})*: an odd sequence of digits (0 or 2*n digits). If the even sequence cannot be null, use ([0-9]{2})+ instead.






                  share|improve this answer














                  You can achieve it with this regexp: ^[a-z0-9]*[a-z]+([0-9]{2})*$



                  Explanation :





                  • [a-z0-9]*[a-z]+: a string of at least one character terminated by a non digit one


                  • ([0-9]{2})*: an odd sequence of digits (0 or 2*n digits). If the even sequence cannot be null, use ([0-9]{2})+ instead.







                  share|improve this answer














                  share|improve this answer



                  share|improve this answer








                  edited Nov 12 at 12:29

























                  answered Nov 12 at 11:54









                  Amessihel

                  1,9631723




                  1,9631723






























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