Posts Tagged ‘math pi’

EXPORTED NAMES

 

After importing a package, you can refer to the names it exports.

In Go, a name is exported if it begins with a capital letter.

Foo is an exported name, as is FOO. The name foo is not exported.

Run the code. Then rename math.pi to math.Pi and try it again.

Example :

package main

import (
“fmt”
“math”
)

func main() {
fmt.Println(math.pi)
}

output:

prog.go:9: cannot refer to unexported name math.pi
prog.go:9: undefined: math.pi

after renaming math.pi to math.Pi

package main

import (
“fmt”
“math”
)

func main() {
fmt.Println(math.Pi)
}

output:

3.141592653589793

PACKAGES

 

Every Go program is made up of packages.

Programs start running in package main.

This program is using the packages with import paths "fmt" and"math".

By convention, the package name is the same as the last element of the import path.

Example:

package main

import (
“fmt”
“math”
)

func main() {
fmt.Println(“Happy”, math.Pi, “Day”)
}

output :

Happy 3.141592653589793 Day