package main
import ("fmt")
func main() {
var i = 3.141
fmt.Printf("%e\n", i)
fmt.Printf("%f\n", i)
fmt.Printf("%.2f\n", i)
fmt.Printf("%6.2f\n", i)
fmt.Printf("%g\n", i)
}
3.141000e+00 3.141000 3.14 3.14 3.141