What are the differences between using JSON arrays vs JSON objects? [duplicate]

The difference between an array and an object is that

Objects are set up using a key and value like:

person.age = 15;

If the key value is a variable, then one could access it like:

var key = "age";
alert(person[key]);

Arrays use an integer[1] index and take a value.

player[1].score += 1000;

[1] Yes, I know, in JavaScript the integer index is really turned into a string behind the scenes. Ignore that. Think of arrays taking an integer value ESPECIALLY when you think of JSON.