I have an array with multiple variables defined in it. But when trying to set each of them to 0 I get an error that states the first variable of the array is undefined.

Here is what I have:

```
var keys = [key1, key2, key3, etc...];

function loadKeys(){
    for(i=0;i<36;i++) {
        keys[i] = 0;
    }
}

```