Currently in Beta 🌸🌸

# Numbers

Arbitrary-precision fixed-point decimal numbers.

Ghost has a single numberic type; arbitrary-precision fixed-point decimals. While most other languages contain representations for integers, floats, doubles, etc., we found that having just a single number type was easier to use even at the slight cost of performance.

Because Ghost uses an arbitrary-precision fixed-point decimal system, it is extremely accurate. Number values look like you expect from other languages:

``````0
1234
-5678
0.001
3.14159
12.34
-1.76
``````

## Precision

Float point numbers (or any binary floating point type) can't represent fractional decimals (`0.1`) precisely. When adding and subtracting them repeatedly will cause rounding errors.

For example, let's consider this code in Go:

``````package main

import "fmt"

func main() {
var n float64 = 0

for i := 0; i < 1000; i++ {
n += .01
}

fmt.Println(n)
}
``````

You might expect it to print `10`, but it in fact prints `9.999999999999831`. This may not be so much of an issue, but if you were having to calculate with extreme precision (such as money), you could find yourself short a few dollars in some extreme cases.

If you were to run the same program above in Ghost, you'd find that the result does come out to exactly `10`:

``````value = 0

for (i = 0; i < 1000; i = i + 1) {
value = value + 0.01
}

print(value)

// expected value: 10
``````
Numbers in Ghost can only represent numbers with a maximum of 2^31 digits after the decimal point.

## Scientific Notation

Numeric values can be represented in scientific notation by using `e`. This returns a value multiplied by the specified power of `10`.

``````1.1    // expected value: 1.1
1.1e0  // expected value: 1.1
1.1e1  // expected value: 11.0
1.1e2  // expected value: 110.0
1.1e3  // expected value: 1100.0
8e-2   // expected value: 0.08
``````

## Methods

### `round()`

The `round()` method rounds the given number to the nearest integer to the specified precision.

``````value = 123.4.round()

// expected value: 123
``````
``````value = 123.456.round(1)

// expected value: 123.5
``````

### `toString()`

The `toString()` method returns the given number as a string.

``````value = 3.141592.toString()

// expected value: "3.141592"
``````