go 練習題 : 閉包 - 費氏數列

費氏.go

package main

import "fmt"

// fibonacci is a function that returns
// a function that returns an int.
func fibonacci() func() int {

	a := 0
	b := 0

	return func() int {
		if a == 0 && b == 0 {
			b = 1
			return 0
		} else if a == 0 && b == 1 {
			a = 1
			b = 0
			return 1
		} else if a == 1 && b == 0 {
			b = 1
			return 1
		}

		o := a + b
		a = b
		b = o

		return o
	}
}

func main() {
	f := fibonacci()
	for i := 0; i < 10; i++ {
		fmt.Println(f())
	}
}