• Dart

var s = x.toStringAsFixed(2);

• C

sprintf(s, "%.2f", x);

• C++

auto s = std::format("{.2f}", x);

• C++

std::array<char, 23> buffer;
std::string s{};
if (auto [ptr, ec] = std::to_chars(buffer.data(), buffer.data() + buffer.size(), x, std::chars_format::fixed, 2); ec == std::errc{}) {
  s = std::string(buffer.data(), ptr);
} else {
  s = std::make_error_code(ec).message();
}

• C++

std::stringstream ss;
ss << std::fixed << std::setprecision(2) << x;
s = ss.str();

• C#

string s = $"{x:F2}";

• D

string str = format("%.2s", x);

• Elixir

s = Float.to_string(x, decimals: 2)

• Erlang

S = io_lib:format("~.2f", [X]).

• Fortran

  write (unit=s,fmt="(F20.2)") x

• Go

s := fmt.Sprintf("%.2f", x)

• Haskell

s <- showFFloat (Just 2) x ""

• JS

num.toFixed(2)

• Java

BigDecimal d = new BigDecimal(x);
String s = "%.2f".formatted(d);

• Java

String s = String.format("%.2f", x);

• Java

NumberFormat f = getNumberInstance();
f.setRoundingMode(HALF_UP);
f.setMaximumFractionDigits(2);
String s = f.format(x);

• Java

MathContext m = new MathContext(3, HALF_UP);
BigDecimal d = new BigDecimal(x, m);
String s = d.toPlainString();

• Java

String s = "%.2f".formatted(x);

• Kotlin

s = "%.2f".format(x)

• Lisp

(setf s (format nil "~$" x))

• Lua

s = string.format("%.2f",x)

• PHP

$s = sprintf('%.2f', $x);

• Pascal

s := format('%.2f',[ x]);

• Perl

$s = sprintf "%.2f", $x;

• Python

s = f'{x:.2f}'

• Python

s =  '{:.2f}'.format(x)

• Python

s = '%.2f' % x

• Python

s = format(x, '.2f')

• Ruby

s = "%.2f" % x

• Rust

let s = format!("{:.2}", x);