Idiom #142 Hexadecimal digits of an integer

Assign to string s the hexadecimal representation (base 16) of integer x.

E.g. 999 -> "3e7"

char s[32];
snprintf(s, sizeof(s), "%x", i);

#include <sstream>

std::ostringstream stream;
stream << std::hex << x;
s = stream.str();

Demo

template <typename I>
std::string n2hexstr(I w, size_t hex_len = sizeof(I)<<1) {
    static const char* digits = "0123456789ABCDEF";
	std::string str(hex_len, '-');
    for (size_t i=0, j=(hex_len-1)*4 ; i<hex_len; ++i,j-=4)
       str[i] = digits[(w>>j) & 0x0f];
	return str;
}

#include <sstream>

using namespace std;
stringstream f;
f << hex << x;
string s {f.str()};

String s = x.ToString("x")

import std.format;

s = format("%x", x);

import std.conv;

s = to!string(x, 16);

var s = x.toRadixString(16);

s = Integer.to_string(x, 16)

S = io_lib:fwrite("~.16B",[X]).

write (*,'(Z8.8)') x

import "strconv"

s := strconv.FormatInt(x, 16)

Demo
Doc

import "fmt"
import "math/big"

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

Demo
Doc

import Text.Printf (printf)

s :: String
s = printf "%x" 999

const s = x.toString(16)

String s = Integer.toHexString(x);

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

import java.util.HexFormat;

String s = HexFormat.of().toHexDigits(x);

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

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

$s = dechex($x);

Demo
Doc

S := Format("%x", [x]);

uses sysutils;

s := IntToHex(x);

my $s = sprintf("%x", $i);

s = hex(x)

s = format(x, 'x')

s = '%x' % x

from string import hexdigits

digits = hexdigits[:16]
def parse(value):
    if value < 16:
        return digits[value]
    n, index = divmod(value, 16)
    return parse(n) + digits[index]
s = parse(x)