Airkit supports the standard subtraction operator `-`. It is used to subtract Number values from other Numbers and Currency values from other Currencies.

# Example

## Subtracting Numbers

The following example shows how the subtraction operator is used to subtract the Number 2 from the Number 3. Note that it returns a another Number: 1, 2 less than 3:

``````3 - 2 -> 1
``````

## Subtracting Currency

The subtraction operator can be used to subtract Currencies provided the Currency values have the same currency code. For instance, say you have two Currency values, `currency_1` and `currency_2`, defined as follows:

``````currency_1 -> {
"amount": 3000,
"code": "USD",
"precision": 2
}
currency_2 -> {
"amount": 1000,
"code": "USD",
"precision": 2
}
``````

`currency_1` and `currency_2` both represent money in US dollars, so one can be subtracted by the other using the subtraction operator:

``````currency_1 - currency_2 -> {
"amount": 2000,
"code": "USD",
"precision": 2
}
``````

Airscript supports negative Currency values, so it is also possible to use the subtraction operator to subtract `currency_1` from `currency_2`, as follows. Note that the resulting Currency has a negative amount value:

``````currency_2 - currency_1 -> {
"amount": -2000,
"code": "USD",
"precision": 2
}
``````

Currency values cannot be subtracted if they do not have matching currency codes. For example, say there is a third Currency value, `currency_3`, in Euros rather than dollars, defined as follows:

``````currency_3 -> {
"amount": 2000,
"code": "EURO",
"precision": 2
}
``````

Attempting to use the subtraction operator to subtract `currency_3` from `currency_1` will result in an error, because the subtraction operator cannot subtract euros from US dollars:

``````currency_1 + currency_3 -> ERROR
``````