Am looking to identify the second digit that should be matching to digit 9 in a length of 19 numbers string, how to do that using Regex, please let me know.
Ex: 8934567890098765438
dentify the starting 2nd character should match 9 digit only and length of the string should be greater than 18
I have tried (?!^.[9])[0-9]{18}, [^.[9][0-9]{18} different ways, but am getting the right one.
CodePudding user response：
You can use a capture group to capture the 9 digit, and match 17 or more chars after it to match at least 19 digits in total:
^\d(\9)\d{17,}$
Or using a positive lookbehind, matching only a 9:
(?<=^\d)9(?=\d{17,}$)
CodePudding user response：
Use
^\d9\d{17}$
See regex proof.
With lookahead:
^(?=\d9)\d{19}$
See another regex proof.
When matching a substring of a longer string:
\b\d9\d{17}\b
(\b is a word boundary).
CodePudding user response：
^(?=.9)\d{19,}$
^(?=.9) : Second character is 9.
\d{19,}$: 19 or more digits