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Can't call my method on object from arraylist

So my problem is: I am trying to call the getName () method from the Achiv class on the ArrayList in the printAchiv () method located in the Achievements script and it clearly does not work.

Here is the error I am getting on this line in the Achievements script: -> Debug.Log ("Achiv" + i + ":" + achivList [i] .getName ());

Enter object' does not contain a definition for

getName 'and no extension method getName' of type

object' can be found (are you missing using directive or assembly reference?)

I'm just trying to access the var "name" value from obejct in a collection.

Achiv class

using UnityEngine;
using System.Collections;

public class Achiv : MonoBehaviour {

        public string name;

        public Achiv(string name )
        {
            this.name= name;
        }

        public string getName()
        {
            return name;
        }
}

Script achievements

    using UnityEngine;
    using System.Collections;

    public class Achievements: MonoBehaviour {

        public  ArrayList achivList = new ArrayList();

        void Start () 
        {
            achivList.Add (new Achiv("First name", "Descirptionn", false));
            achivList.Add (new Achiv("Second name", "Descirptionnn", false));

            printAchiv();
        }

        void printAchiv(){

            for (int i = 0; i <= achivList.Count - 1; i++)
                Debug.Log("Achiv "+i+": "+ achivList[i].getName());
        }   
    }
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3 answers


Use List<Achiv>

instead ArrayList

. ArrayList

is archaic and type safe should not be used anymore.

The pointer ArrayList

returns object

why you are getting the error. Try the following.

public List<Achiv> achivList = new List<Achiv>();


Besides,

  • Do not publish List

    publicly, prefer ReadOnlyCollection

    or IEnumerable

    .
  • Prefer foreach

    over for

    unless there is a good reason.
  • printAchiv

    does not match the correct naming convention. In C # we are using "CamelCase", rename it to printAchiv

    .
  • get / set methods are for java style languages ​​that don't support properties. In C #, we use properties instead. Create a property viz Name

    .
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ArrayList works with objects. You need to pass the result of indexing the array to Achiv:



(achivList[i] as Achiv).getName()
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The problem is that the elements inside ArrayList

are stored as object

. Thus, it achivList[i]

returns object

, which the method does not provide getName()

. Or you can add a cast:

            Debug.Log("Achiv "+i+": "+ (Achiv)achivList[i].getName());

or you can switch to a generic list:

using UnityEngine;
using System.Collections.Generic;

public class Achievements: MonoBehaviour {


    public  List<Achiv> achivList = new List<Achiv>();


    void Start () {

        achivList.Add (new Achiv("First name", "Descirptionn", false));
        achivList.Add (new Achiv("Second name", "Descirptionnn", false));


        printAchiv();

    }


    void printAchiv(){

        for (int i = 0; i <= achivList.Count - 1; i++)
        {

            Debug.Log("Achiv "+i+": "+ achivList[i].getName());
        }
    }   
}
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