Access the x, y, z components using [0], [1], [2] respectively.
var p : Vector3; p[1] = 5; // the same as p.y = 5
using UnityEngine; using System.Collections; public class ExampleClass : MonoBehaviour { public Vector3 p; void Example() { p[1] = 5; } }
import UnityEngine import System.Collections public class ExampleClass(MonoBehaviour): public p as Vector3 def Example() as void: p[1] = 5