System.Array.IndexOf iterating when it should not

Question

I have an Array of bools and when the function Key1Pushed() is called I want to iterate through the array setting them all to false, except for the bool key1 which I want to set to true.

I believe this code should work however whenever I call Key1Pushed() I encounter 2 issues:

System.Array.IndexOf(allKeys, key1) returns 1, when i = 0; returns 2, when i=1, and so on until it returns -1, when i = 7. I don't know why it's iterating, and I dont know why it starts with returning 1.

Even though in every case i does not equal what System.Array.IndexOf(allKeys, key1) returns, it passes the first if condition and sets all of the values in my array to true.

  public class InputKey : MonoBehaviour {
     
                         public bool[] allKeys;
                         private bool key1;
                         private bool key2;
                         private bool key3;
     
                     void Start () {
                      allKeys = new bool[] { key1, key2, key3 };
                     }
                     
                     public void Key1Pushed () {
                             for(int i = 0; i < allKeys.Length; i++) {
                                 if (i == System.Array.IndexOf(allKeys, key1)) {
                                     allKeys [i] = true;
                                 } else if (i != System.Array.IndexOf(allKeys, key1)) {
                                     allKeys [i] = false;
                                 }
                             }
                     }

Any help would be appreciated,

Thank you

Answer 1

A bool is a value type, so when you assign a boolean to another boolean variable, you don't create a reference to the original boolean, instead the value of the first gets copied to the second. In other words, you don't get 2 variables referencing the same piece of data, you get 2 separate variables with the same value.

You can easily test this

 key1 = false;
 allKeys = new bool[] { key1 };
 key1 = true;
 
 Debug.Log(key1); // true
 Debug.Log(allKeys[0]); // false
 // Changing key1 doesn't change the copy in the array & vice versa

For the same reason IndexOf() doesn't work as you probably think it does in this case. Because bool is a value type, IndexOf will just find the first index that holds the same value as the second parameter. You can test this too

 key1 = false;
 key2 = false;
 allKeys = new bool[] { key1, key2 };
 
 Debug.Log(System.Array.IndexOf(allKeys, key1))); // 0
 Debug.Log(System.Array.IndexOf(allKeys, key2))); // 0
 // Both return 0 because index 0 contains false and both
 // lines check to find the index of "false" in the array

Since your Key1Pushed() handles only 1 index/key, you don't have to use IndexOf(). I believe you could just do

 for(int i = 0; i < allKeys.Length; i++) {
     allKeys [i] = i == 0; // set index 0 to true, others to false
 }

You could even make the index to be a function parameter

 public void KeyPushed (int keyIndex) {
     for(int i = 0; i < allKeys.Length; i++) {
          allKeys [i] = i == keyIndex;
     }
 }

System.Array.IndexOf iterating when it should not

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