Regular expression to replace middle chars of a string

Question

I would like to replace middle 4 characters of a string with ****

For example: ABCDEFG should become AB****G

Please suggest a Regex to achieve this.

Note: The length of the string is always same.

Answer 1

Found the solution that I was looking for:

var s="ABCDEFG"
var reg=/\b(\w{2})\w+(\w)\b/g

s.replace(reg, '$1**$2');

output: AB****G

This will replace all the middle chars except first 2 and last 1 char in a string.