Check slected mission status in inspector

It looks like you are looking for a Hashtable. A hashtable stores a variable number of key and value pairs.

A key is an object that is used like an address, usually a string like a user name: "guest1", "Leroy Jenkins", etc.

A value is what you are trying to store, this can be anything. An example is a password: "letmein", "p4ssw0rd", etc.

In the username/password example, whenever I input the username to the Hashtable, it will spit out the associated password. I can then check that against what the user said is their password and accept or deny a login request.

Hashtables are very processor efficient usually finding your stored value in a short, constant amount of time no matter how many objects are stored, but can become major memory hogs if there is too much information stored in them.

Here is an example of how to use a Hashtable (in C#, not javascript):

 using UnityEngine;
 using System.Collections;
 using System.Collections.Hashtable;
 Class Example : MonoBehaviour
 {
     int SIZE = 32;
     void Start()
     {
         //creates an empty Hashtable that can store SIZE key/value pairs
         Hashtable quests = new Hashtable(SIZE);
         //will automatically resize if more than SIZE keys are added.
 
         //you might need to use this if it says it can't find the namespace
             //System.Collections.Hashtable ... = new System.Collections.Hashtable();
 
         //creates a new key "MainQuest" and assigns the value -1 to it.
         quests.Add("MainQuest", -1);
         Debug.Log(quests["MainQuest"]);//outputs -1
 
         //thorws an exception if a key already exists
         try
         {   quests.Add("MainQuest", 0);//throws an exception    }
         catch
         {   Debug.Log("The value \"MainQuest\" already exists!");    }
         Debug.Log(quests["MainQuest"]); //outputs -1
 
         //can return and change values in this manner
         quests["MainQuest"] = 1;
         Debug.Log(quests["MainQuest"]);//outputs 1
 
         //can create new key/value pairs in this manner
         quests["SideQuest"] = 2;
         Debug.Log(quests["SideQuest"]);//outputs 2
     }
 }

There is a lot more to Hastables than I have written here, but these are the basics to using them.