• Pascal

var
  _x: String;
begin
  _x := ParamString(1);
end.

• C

void main(int argc, char *argv[])
{
    char *x = argv[1];
}

• C++

int main(int argc, char *argv[])
{
 vector<string> args(1 + argv, argc + argv);

 string x = args.at(0);
}

• C#

static void Main(string[] args)
{
    string x = args[0];
}

• D

auto x = args[1];

• Dart

main(args) {
  var x = args[0];
}

• Fortran

  character(len=:), allocatable :: x
  integer :: n
  call get_command_argument (1, length=n)
  allocate (character(n):: x)
  call get_command_argument (1, x)

• Go

x := os.Args[1]

• Haskell

x <- return.head =<< System.Environment.getArgs

• JS

const x = process.argv[2]

• Java

public static void main(String[] args) {
    if (args.length != 0) {
        String x = args[0];
    }
}

• Java

String x = args[0];

• Lua

x = arg[1]

• PHP

$x = $argv[1];

• Perl

$x = $ARGV[0];

• Python

x = sys.argv[1]

• Ruby

x = ARGV.first

• Rust

let x = env::args().nth(1).unwrap_or("".to_string());

• Rust

let first_arg = env::args().skip(1).next();

let fallback = "".to_owned();
let x = first_arg.unwrap_or(fallback);