go 类型练习

package main

import (
    "fmt"
    "math"
)

type rect struct {
    width, height float32
}
type cir struct {
    r float32
}
type myInt int64

func (a myInt) area() myInt {
    return a
}

func (a *rect) area() float32 {
    a.height = 12
    return (*a).height * (*a).width
}
func (a cir) area() float32 {
    a.r = 1
    return (a).r * (a).r * math.Pi
}

func main() {

    r1 := rect{10, 10}
    r2 := cir{10}
    r3 := myInt(999)
    fmt.Println(r1.area())
    fmt.Println(r2.area())
    fmt.Println(r3.area())
    fmt.Println("Hello World")
    fmt.Println(r1.height)
    fmt.Println(r2.r)
}