Why aren't currency values returned by the Square Connect API formatted with decimals?

Question

Here's a snippet of data returned by the API. The amount tendered in the transaction was actually $1.00 USD, but the API returns a value of 100. Is this normal? Should I expect to have to add the decimal and decimal places, myself?

{
    "type": "CASH",
    "name": "Cash",
    "total_money": {
        "currency_code": "USD",
        "amount": 100
    },
    "tendered_money": {
        "currency_code": "USD",
        "amount": 100
    }
}

Answer 1

The problem is that lots of languages, Javascript included, don't have decimals. They have floats instead. And you should never do monetary calculations (that you care about) with floats due to the floating point problem:

• Understanding floating point problems
• How to deal with floating point number precision in JavaScript?
• Is floating point math broken?
• http://docs.sun.com/source/806-3568/ncg_goldberg.html

As such, returning the rates in cents is a good way to remind programmers of this and avoid the temptation of doing financial calculations in floats.