// Draws a 10 meter long green line from the position
// forward along the transform's z-axis.
function Update () {
var forward : Vector3 = transform.TransformDirection(Vector3.forward) * 10;
Debug.DrawRay (transform.position, Vector3.forward * 10, Color.green);
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
void Update() {
Vector3 forward = transform.TransformDirection(Vector3.forward) * 10;
Debug.DrawRay(transform.position, Vector3.forward * 10, Color.green);
}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

def Update():
forward as Vector3 = (transform.TransformDirection(Vector3.forward) * 10)
Debug.DrawRay(transform.position, (Vector3.forward * 10), Color.green)