• Lisp

(defparameter *s* (string c))

• Ada

S : constant String := "" & C;

• C

char s[2] = {0};
s[0] = c;

• Clojure

(def s (str c))

• C++

string s { 'c' };

• C#

var s = new string(c, 1);

• C#

string s = c.ToString();

• D

string s = to!string(c);

• Dart

var s=c;

• Elixir

to_string(char)

• Erlang

S = [C]

• Fortran

character(len=:),allocatable :: s
character(len=1) :: c
s=c

• Go

s := fmt.Sprintf("%c", c)

• Haskell

s = [c]

• JS

let s = c

• Java

String s = c + "";

• Java

String s = String.valueOf(c);

• Java

String s = "%s".formatted(c);

• Java

String s = Character.toString(c);

• Java

String s = = new Character(c).toString();

• Kotlin

val s: String = c.toString()

• Lua

s = c

• PHP

$s = (string) $c;

• Pascal

var
  s: string;
begin
  s := 'c';
end.

• Perl

my $s = $c;

• Python

s = c

• Ruby

s = ?c

• Rust

let s = c.to_string();