Sequence repeat validation using Regular expression in javascript

Question

Iam pretty new to regular expressions .I would like to prevent the user from entering in

String data using javascript function with the following condition .

Same sequence of characters cannot be repeated two or more times

  aabhi - is allowed 
 aabbcc -  is allowed

 dayday - not allowed
 abab - not allowed
 ababab - not allowed 
 aaaa - not allowed 

this applies to numbers too .Can someone help me with this ? Thanks in advance

Answer 1

Based on your inputs you can use this regex:

 /(\w{2,})(\1)/

Code:

re = /(\w{2,})(\1)/;

s = 'dayday';
if (re.test(s))
   console.log("invalid);
else
   console.log("valid);