Learn X By Example
Learn X By Example

    Go by Example: Constants

    Go by Example : Constants

    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))
}
    $ go run constant.go 
constant
6e+11
600000000000
-0.28470407323754404

    Next example: For .

    Prev
    Go by Example: Command-Line Subcommands
    Next
    Go by Example: Context