• PHP

function createTempDir(): ?string
{
    $path = rtrim(sys_get_temp_dir(), DIRECTORY_SEPARATOR) . DIRECTORY_SEPARATOR . mt_rand() . microtime(true);
    if (mkdir($path)) {
        return $path;
    }
    return null;
}

• C#

string newDir = Path.GetTempPath() + Guid.NewGuid();
Directory.CreateDirectory(newDir);

• D

string mkTmpDir()
{
    import std.uuid, std.file, std.path;
    string d = buildPath(tempDir, randomUUID.toString);
    if (!d.exists)
    {
        mkdir(d);
        return d;
    }
    else return null;
}

string s;
while (!s.length)
  s = mkTmpDir;

• Go

dir, err := os.MkdirTemp("", "")

• Haskell

withTempDirectory $ \d -> do
  -- do something with d

• JS

const tempDir = await Deno.makeTempDir();

• Java

File folder = new File("/path/");
folder.deleteOnExit();

• Pascal

var
  GUID: TGUID;
  Succes: Boolean;

begin
  CreateGUID(GUID);
  Succes := CreateDir(GetTempDir + GUIDToString(GUID));
end.

• Perl

my $path = tempdir;

• Python

td = tempfile.TemporaryDirectory()

• Ruby

td = Dir.mktmpdir

• Rust

let tmp = TempDir::new("prefix")?;