You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
36 lines
760 B
Go
36 lines
760 B
Go
// 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))
|
|
}
|