Go supports constants of character, string, boolean,
and numeric values.



package main


import (
"fmt"
"math"
)

const declares a constant value.

const s string = "constant"


func main() {
fmt.Println(s)

A const statement can appear anywhere a var
statement can.

const n = 500000000

Constant expressions perform arithmetic with
arbitrary precision.

const d = 3e20 / n
fmt.Println(d)

A numeric constant has no type until it’s given
one, such as by an explicit conversion.

fmt.Println(int64(d))

A number can be given a type by using it in a
context that requires one, such as a variable
assignment or function call. For example, here
math.Sin expects a float64 .

fmt.Println(math.Sin(n))
}
