带字符串的正则表达式包含Java中通配符/ Min，MaxLength的数字

Question

I am new to JavaScript Regular Expressions. Currently I am trying to create a regex on a String that may contain a digit.

Scenario is like following:<

The String may contain a * either before or after or both but not in the middle.

The String length will be a minimum of 2 characters and a maximum of 12 characters (not counting the * ).

Input String Example:

AB1542378522
AC6546457869
OA6546457869

Other valid Strings are:

*154*
*C6*
AB*
AB154237*
*2378522
*C654645
*645
*AB*
*AC6546457869*
OA*

Invalid Strings:

*15*4
*15*4*
*A*B15*42*37*

Only the * wildcard is supported, no other special character allowed in input. For example in above input string AB , AC and OA are valid first two character but not AA , AX , OS ... then it will follow 10 digits at max.

I am unable to create such regex that covers above use-cases. My code is getting exhausted by if else branching. If I find any answer I will post it in a comment. Make a comment for any confusion.

Answer 1

Try to use this pattern:

/^\*?(?=[^*]{2})[A-Z]{0,2}[0-9]{0,10}\*?$/

pattern explanation:

^           begining of the string
\*?         optional * 
(?=[^*]{2}) check if at least 2 characters that are not * follows
[A-Z]{0,2}  between zero and 2 letters
[0-9]{0,10} between zero and 10 digits
\*?         optional *
$           end of the string