Question

Given the following string in C#, how would I insert a character in between each character in the string?

For example:
"Hello Sunshine"
would become
"H.e.l.l.o. .S.u.n.s.h.i.n.e"

What is the most efficient, fastest way of doing this in C#?

Answer 1

How about:

string result = string.Join(".", someString.AsEnumerable());

This hides most of the complexity, and will use a StringBuilder internally.