替换字符串中除最后4个字符外的所有字符

Question

Using Go, how do I replace all characters in a string with "X" except the last 4 characters?

This works fine for php/javascript but not for golang as "?=" is not supported.

\w(?=\w{4,}$)

Tried this, but does not work. I couldn't find anything similar for golang

(\w)(?:\w{4,}$)

JavaScript working link

Go non-working link

Answer 1

Create a Regexp with

re := regexp.MustCompile("\w{4}$")

Let's say inputString is the string you want to remove the last four characters from. Use this code to return a copy of inputString without the last 4 characters:

re.ReplaceAllString(inputString, "")

Note: if it's possible that your input string could start out with less than four characters, and you still want those characters removed since they are at the end of the string, you should instead use:

re := regexp.MustCompile("\w{0,4}$")