Be concise.

Be useful.

All contributions dictatorially edited by webmasters to match personal tastes.

Please do not paste any copyright violating resource.

Please try to avoid dependencies to third-party libraries and frameworks.

Other implementations
import "strconv"
s := strconv.FormatInt(x, 16)
import "fmt"
import "math/big"
s := fmt.Sprintf("%x", x)
import std.conv;
s = to!string(x, 16);
import std.format;
s = format("%x", x);
uses sysutils;
s := IntToHex(x);
s = x.to_s(16)
s = string.format("%x",x)
s = format(x, 'x')
let s = format!("{:X}", x);

$s = dechex(999);
char s[32];
snprintf(s, sizeof(s), "%x", i);
let s = x.toString (16)