Assign to c the value of the i-th character of the string s.Make sure to properly handle multi-byte characters. i is the character index, which may not be equal to the byte index.
c = s[i]
c = s(i:i)
c := []rune(s)[i]
char c = s.charAt(i);
LazUtf8
c := Utf8Copy(s,i,1);
c := s[i];
use utf8; $c = substr $s, $i, 1;
let c = s.chars().nth(i).expect("s is too short");
No security, no password. Other people might choose the same nickname.