IndexOutOfRangeException: How to FIX it?

So, I'm following this tutorial series on YouTube and I have gotten stuck! Here is the error message:

IndexOutOfRangeException: Array index is out of range. (wrapper stelemref) object:stelemref (object,intptr,object) gun.Start () (at Assets/gun.js:22)

And here is the code:

 public enum gunType{ Automatic, semiAutomatic, Shotgun, BurstFire}
 
 var spark : Transform;
 
 var shotNumber : int;
 var damage : float;
 var fireRate : float;
 var spread : float;
 var recoil : float;
 var weight : float;
 var type : gunType;
 var magSize : int;
 var ammo : int;
 
 private var mag : int;
 private var nextFire = 0.0;
 private var SparkArrays : Transform[];
 
 function Start() {
     SparkArrays = new Transform[shotNumber];
     for(var i=0;1<SparkArrays.Length;i++) {
         SparkArrays[i] = Instantiate(spark, spark.position, spark.rotation);
     }
 }
 
 function Update () {
     switch(type) {
         case gunType.Automatic :
             if(Input.GetButton("Fire1")&&Time.time > nextFire) {
                 nextFire = Time.time + fireRate;
                 FireA();
             }
             break;
         case gunType.semiAutomatic :
             if(Input.GetButtonUp("Fire1")&&Time.time > nextFire) {
                 nextFire = Time.time + fireRate;
                 FireA ();
             }
             break;
         case gunType.semiAutomatic :
             if(Input.GetButton("Fire1")&&Time.time > nextFire) {
                 nextFire = Time.time + fireRate;
                 FireS ();
             }
             break;
     }
 }
 
 function FireS () {
     for(var i=0;i<SparkArrays.Length;i++){
         var hit : RaycastHit;
         var BulletDirection = transform.TransformDirection(new Vector3(Random.Range(-spread,spread)*0.002,Random.Range(-spread,spread)*0.001,1));
         
         if(Physics.Raycast(transform.position, BulletDirection, hit, Mathf.Infinity)) {
             if(hit.transform.gameObject.tag=="Player")
                 hit.transform.SendMessage("M_damage", damage);
             SparkArrays[i].position = hit.point;
         }
         
     }
     
     mag--;
 }
 
 function FireA () {
 
     var hit : RaycastHit;
     var BulletDirection = transform.TransformDirection(new Vector3(Random.Range(-spread,spread)*0.002,Random.Range(-spread,spread)*0.001,1));
     
     if(Physics.Raycast(transform.position, BulletDirection, hit, Mathf.Infinity)) {
         if(hit.transform.gameObject.tag=="Player")
             hit.transform.SendMessage("M_damage", damage);
         spark.position = hit.point;
     }
     
     mag--;
 }

Any help is appreciated!!!