How do I save external JSON data to a JavaScript variable?

Question

I have an JSON file (I cannot change), data.json that looks like:

{
    "Data": [
        {
            "AccountId": "1234",
            "ClientId": "12345567",
            "Amount": 140.68,
            "BalanceYear": "2015",
            "AccountName": "Master"
        },
    "Success": true,
    "Errors": null
}

I am bringing it into my .js file as such:

 <script type="text/javascript" src="./data.json"></script>

And I want to iterate through it with JSON.parse.

My only issue is getting the data from the .json file to the JSON.parse function.

var mydata = JSON.parse(???);

Would anyone know how I can do this?