Add characters into a string

[ritchie75]

How do i add characters into a string?

Ex: abc cde efg asdfas asdf asdf wer gher

add "," to each word except first one.

abc cde, efg, asdfas, asdf, asdf, wer, gher

[whodgson]

string s1= {--------------}
string s2={........... ......)
string s3= s1+s2
cout<<s3 //prints ------------............... ...