How to replace the last two '/' characters from a string in Go

profilePicture := strings.Replace(tempProfile, "/", "%2F", -2)

I tried this code but its replace all / in the string

tempProfile = "https://firebasestorage.googleapis.com/v0/b/passporte-b9070.appspot.com/o/profilePicturesOfAbmin/original/1492674641download (3).jpg?alt=media"

the result which want is

tempProfile = "https://firebasestorage.googleapis.com/v0/b/passporte-b9070.appspot.com/o/profilePicturesOfAbmin%2Foriginal%2F1492674641download (3).jpg?alt=media"

First, from the documentation:

> Replace returns a copy of the string s with the first n non-overlapping instances of old replaced by new. If old is empty, it matches at the beginning of the string and after each UTF-8 sequence, yielding up to k+1 replacements for a k-rune string. If n < 0, there is no limit on the number of replacements. (Emphasis added)

Which explains why your -2 isn't working.

The simplest approach to your stated problem is probably something like this:

parts := strings.Split(tempProfile, "/")
parts = append(parts[:len(parts)-3], strings.Join(parts[len(parts)-3:], "%2F"))
profilePicture := strings.Join(parts, "/")

But a better approach is probably to do proper URL encoding with the url package.