Idiom #23 Convert real number to string with 2 decimal places

Given a real number x, create its string representation s with 2 decimal digits following the dot.

Java

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

Java

import java.math.BigDecimal;

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

Java

import static java.math.RoundingMode.HALF_UP;
import java.math.BigDecimal;
import java.math.MathContext;

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

Java

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

Java

import static java.math.RoundingMode.HALF_UP;
import static java.text.NumberFormat.getNumberInstance;
import java.text.NumberFormat;

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

#include <stdio.h>

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

#include <format>

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

#include <iomanip>
#include <sstream>

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

#include <charconv>
#include <array>

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();
}