# Constant overflows int

yourbasic.org/golang

Why doesn’t this code compile?

```
const n = 9876543210 * 9876543210
fmt.Println(n)
```

```
../main.go:2:13: constant 97546105778997104100 overflows int
```

## Answer

The untyped constant `n`

must be converted to a type before it can be
assigned to the `interface{}`

parameter in the call to `fmt.Println`

.

`fmt.Println(a ...interface{})`

When the type can’t be inferred from the context, an untyped constant
is converted to a `bool`

, `int`

, `float64`

, `complex128`

, `string`

or `rune`

depending of the format of the constant.

In this case the constant is an integer, but `n`

is larger
than the maximum value of an `int`

.

However, `n`

can be represented as a `float64`

.

```
const n = 9876543210 * 9876543210
fmt.Println(float64(n))
```

```
9.75461057789971e+19
```

For exact representation of big numbers, the math/big package implements arbitrary-precision arithmetic. It supports signed integers, rational numbers and floating-point numbers.