Need Help with Shooting Script c#

First of all, you need to prepare the following things:

1) A bullet prefab. you can create a prefab by dragging an object in the scene to your project panel.

You can try to create a cube by clicking Create button on the top of your hierarchy. Then you can rename the cube and drag it into your project panel. You can see your cube's name become blue. That means this object has became a prefab.

2) A script attached to the bullet prefab. This script will be in charge of moving your bullet, and detect collision. I didn't write collision code here because you haven't got any enemy yet. The bullet will "destroy"(deactivate) itself when it goes out of the camera.

 // BulletScript.cs
 using UnityEngine;
 using System.Collections;
 
 public class BulletScript : MonoBehaviour {
     
     public float bulletSpeed = 5f;
     void Update () {
         transform.Translate(Vector3.right * bulletSpeed * Time.deltaTime);
     }
     
     void OnBecameInvisible () {
         this.gameObject.SetActive(false);
     }
 }

3) A script attached to your character/space ship.

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic; // Remember to add this line, otherwise the List won't work
  
 public class Shooting : MonoBehaviour {
  
     public float bulletSpeed = 5f;
     public GameObject bullet; // Drag and drop your x axis bullet here
     List<GameObject> bulletList; // This is a List of bullets, you can just think it as an array at this point
     // For more information of List, check the tut here:
     // http://unity3d.com/learn/tutorials/modules/intermediate/scripting/lists-and-dictionaries
     // It's short (5 mins) and informative
     public int maxBulletOnX = 8; // The limit of bullet on x axis 
     // You can always adjust the limit in inspector without going into the code
  
     void Start () {
         bulletList = new List<GameObject>();
         for (int i = 0; i < maxBulletOnX; i++)
         {
             bulletList.Add(Instantiate(bullet,Vector3.zero,Quaternion.identity));
             // What this line does is to "instantiate" the prefab (aka. your bullet you want to shoot)
             // Instantiate is good for cloning duplicated object like bullet
             // For more information of Instantiate, check here:
             // http://docs.unity3d.com/Documentation/Manual/InstantiatingPrefabs.html
             // It's usually bad to instantiate/destroy at runtime, but you don't have to worry about it at this point
             bulletList[i].GetComponent<BulletScript>().bulletSpeed = bulletSpeed;
             // This line will access your bullet's script and set the speed for it.
             // For more information of accessing another script, check here:
             // http://unitygems.com/script-interaction1/
             bulletList[i].SetActive(false);
             // This will de-activate your bullet when started up
         }
     }
     
     void Shoot () {
         GameObject temp = bulletList.Find(go => go.activeInHierarchy == false});
         // This is called lambda expression. You don't have to know what this is now.
         // What it does is to find bullet that is waiting to be used.
         if (temp != null)
         {
             temp.transform.position = transform.position + offset;
             // You might want modify the position value by yourself
             // What this does is to set the bullet at right place, aka where you shoot
             // Now it shoots from the center of your character
             temp.SetActive(true);
         }
     }
  
     void Update () {
        if (Input.GetMouseButtonDown(0)) // 0 means left click
        {
             Shoot();
        }
     }
 }

It might be too complex for a beginner, but I think you can google a huge amount of beginner tutorial for a shooting game.

You need to replace the destroy part with this:

 if (myTransform.position.x > Player.transform.position.x+8 || myTransform.position.x < (Player.transform.position.x+8)*-1)
 {
 DestroyObject(this.gameObject);
 }

Which basically gets the player position x and adds 8 to it and it checks both left and right side, of course you need to add

 public Transform Player;

To make it shoot both sides you need to use a bool and control it with Input.GetKey to know if the player is going left or right.

 bool facingRight;
 
 void Update()
 {
   if (Input.GetKeyDown(KeyCode.LeftArrow))
   {
     facingRight = false;
   } else if (Input.GetKeyDown(KeyCode.RightArrow))
   {
     facingRight = true;
   }
 }

I hope you know what this code does, next thing is to finally move the bullet the right direction.

 void Update()
 {
   if (facingRight)
   {
     myTransform.Translate(BulletSpeed*Time.deltaTime,0,0);
   } else myTransform.Translate(BulletSpeed*Time.deltaTime*-1,0,0);
 }

The final result looks like this:

 using UnityEngine;
 using System.Collections;
  
 public class Shooting : MonoBehaviour {
  
     public int BulletSpeed = 5;
     public GameObject Bullet;
     public Transform Player;    
 
     private Transform myTransform; 
 // variables are private by default in C# so you don't need it
     bool facingRight;
  
     void Start () 
     {
        myTransform = transform;
     }
  
  
     void Update () 
     {
     if (Input.GetKeyDown(KeyCode.LeftArrow))
     {
     facingRight = false;
     } 
     else if (Input.GetKeyDown(KeyCode.RightArrow))
     {
     facingRight = true;
     }
 
       if (facingRight)
       {
       myTransform.Translate(BulletSpeed*Time.deltaTime,0,0);
       } else myTransform.Translate(BulletSpeed*Time.deltaTime*-1,0,0);
 
 if (myTransform.position.x > Player.transform.position.x+8 || myTransform.position.x < (Player.transform.position.x+8)*-1)
 {
 DestroyObject(this.gameObject);
 }
     }
 }

I'm sorry the code formatting messed up at the end..

The problem inlies where you have

if (myTransform.Position.x >8)

{ destroyObject (this.gameobject) }

Form what you are trying to accomplish I do not think you need that piece of code. What it is actually saying is if the object is beyond 8 on the x axis the object will be destroyed. when your player goes past 8 and you try to fire the object is destroyed instantly.

If you are trying to destroy the object when it hits a player i am lost as i myself am a beginner at C# (i'm tying to figure out how to do that very thing!) but i do hope this helps some

Hi there, very cool script @DiligentGear, how would you go about reusing the activation of the deactivated prefab, i tried and failed to do so. Would weneed to code a proper pool with queue or dequeue or is there another way to manage it ? THX

void Fire() //for Guns.... {

     GameObject goli = Instantiate(Bullet, new Vector3(bulletpos.transform.position.x, bulletpos.transform.position.y, bulletpos.transform.position.z), BulletRotation.rotation) as GameObject;       
     goli.GetComponent<Rigidbody>().velocity = goli.transform.forward * speed;
     // Destroy the bullet after 5 seconds
     Destroy(goli, 5.0f);

 }

just call this function and give the position to generate bullet.......... hope it's help you..