Replace multiple characters, by index, in a string quickly

Question

I\'m trying to quickly replace multiple characters in a string with another character such as *

For example, I have a string such as:

string         


        

Answer 1

in base R, besides the method of substring() and for-loop shown by @akrun,, you can use utf8ToInt() and intToUtf8 to make it

v <- utf8ToInt(string)
v[string_indexes_replaced ] <- utf8ToInt("*")
res <- intToUtf8(v)

which gives

> res
[1] "*bc*e*gh*j"