Call a function from string variable in PERL, PHP and C#

PERL

my $function_name = "hello";
&$function_name(10);
function hello() {
  my $param = shift;
  print "hello $paramn";
}

PHP

$function_name = "hello";
$function_name();
function hello($param) {
  echo "hello $paramn";
}

C#

class Program
{
  static void Main(string[] args)
  {
    Type type = typeof(MyReflectionClass);
    MethodInfo method = type.GetMethod("Hello");
    MyReflectionClass c = new MyReflectionClass();
    method.Invoke(c, null);
  }
}

public class MyReflectionClass
{
  public void Hello(int num)
  {
    Console.WriteLine("hello {0}", num.ToString());
  }
}