Modifying a character in a string in Lua

Question

Is there any way to replace a character at position N in a string in Lua.

This is what I\'ve come up with so far:

function replace_char(pos, str, r)
         


        

Answer 1

You should use pos inside your function instead of literal 1 and 3, but apart from this it looks good. Since Lua strings are immutable you can't really do much better than this.

Maybe

 "%s%s%s":format(str:sub(1,pos-1), r, str:sub(pos+1, str:len())

is more efficient than the .. operator, but I doubt it - if it turns out to be a bottleneck, measure it (and then decide to implement this replacement function in C).