C# adding items to an already created Array

[anon39953356]

Hello Unity Community,

I am having a really hard time trying to create a piece of code that would add objects that I would select into an array. I was doing some research and it said that I would only be able to do the array.Add or array.Push in java. Which sucks because our project is in C#, is there any alternative that I could possible look into for this problem Thanks, Nolan Encarnacion

using UnityEngine;
using System.Collections;

public class SelectionManager : MonoBehaviour 
{
    public RaycastHit hit;
    public Ray ray;
    public GameObject[] selection;
    // Use this for initialization

    // Update is called once per frame
    void Update () 
    {
        if ( Input.GetMouseButtonDown(0) )
        {
          ray = Camera.main.ScreenPointToRay (Input.mousePosition);
          if (Physics.Raycast (ray, out hit, 100))
          {
            addtoArray(hit.collider.gameObject);
            Debug.Log(selection);
             //Debug.Log(hit.collider.gameObject.name);
          }
       }

    }
    void addtoArray(gameObject obj)
    {
        selection.Add(obj);
    }
}

[anon85704231]

You generally want to use List for this kind of thing

Add this to the top of the file:

using System.Collections.Generic;

then this instead of your array:

List<GameObject> selection;

Add should work fine then

[Peter_G]

No, you have to recreate the array with its new member. You may as well make it a generic method:

using System.Collections.Generic;

public static class Extensions {

    public static T[] AddItemToArray <T> (this T[] original, T itemToAdd) {

         T[] finalArray = new T[ original.Length + 1 ];
         for(int i = 0; i < original.Length; i ++ ) {
              finalArray _= original*;*_
 _*}*_
 _*finalArray[finalArray.Length - 1] = itemToAdd;*_
 _*return finalArray;*_
 _*}*_
_*}*_
_*```*_
_*<p>So as you can see, it isn't very easy to resize arrays.</p>*_
_*<p>Or, as Mike said right before I posted, you should probably just use a List.  It will handle this for you.</p>*_

[V-Jankaitis]

T AddtoArray(T Org, T New_Value)
{
T New = new T[Org.Length + 1];
Org.CopyTo(New, 0);
New[Org.Length] = New_Value;
return New;
}

[mx_official]

If anyone needed the same script but for models with multiple materials, here you go.

edit: Made fadePerSecond serialized for others who will be using the script in their own way.

using System.Collections.Generic;
using UnityEngine;

public class FadeAlpha : MonoBehaviour
{
    [SerializeField] private float fadePerSecond = 0;
    
    [SerializeField] private List<Material> materials = new List<Material>();

    [SerializeField] private bool moreThanOneMat = false;

 
    void Start()
    {
        // Locating Materials
        if (GetComponent<MeshRenderer>().materials.Length > 1)
        {
            moreThanOneMat = true;

            foreach (Material m in GetComponent<MeshRenderer>().materials)
            {
                materials.Add(m);
            }
        }
    }

    void Update() 
    {
        if (moreThanOneMat == true)
        {
            DropAlphaForAll();
        }
        else
        {
            var material = GetComponent<MeshRenderer>().material;
            var color = material.color;

            if (color.a > 0)
            {
                material.color = new Color(color.r, color.g, color.b, color.a - (fadePerSecond * Time.deltaTime));
            }
            if (color.a < 0)
            {
                material.color = new Color(color.r, color.g, color.b, 0);
            }
        }
    }

    void DropAlphaForAll()
    {
        if (GetComponent<MeshRenderer>().materials.Length > 1)
        {
            foreach (Material mats in materials)
            {
                if (mats.color.a > 0)
                {
                    mats.color = new Color(mats.color.r, mats.color.g, mats.color.b, mats.color.a - (fadePerSecond * Time.deltaTime));
                }
                if (mats.color.a < 0)
                {
                    mats.color = new Color(mats.color.r, mats.color.g, mats.color.b, 0);
                }
            }
        }
    }
}