golang 3. 常量 const iota
阿新 • • 發佈:2021-06-27
package main import "fmt" //const 來定義列舉型別 const ( //可以在const() 新增一個關鍵字 iota, 每行的iota都會累加1, 第一行的iota的預設值是0 BEIJING = 10*iota //iota = 0 SHANGHAI //iota = 1 SHENZHEN //iota = 2 ) const ( a, b = iota+1, iota+2 // iota = 0, a = iota + 1, b = iota + 2, a = 1, b = 2 c, d // iota = 1, c = iota + 1, d = iota + 2, c = 2, d = 3 e, f // iota = 2, e = iota + 1, f = iota + 2, e = 3, f = 4 g, h = iota * 2, iota *3 // iota = 3, g = iota * 2, h = iota * 3, g = 6, h = 9 i, k // iota = 4, i = iota * 2, k = iota * 3 , i = 8, k = 12 ) func main() { //常量(只讀屬性) const length int = 10 fmt.Println("length = ", length) //length = 100 //常量是不允許修改的。 fmt.Println("BEIJIGN = ", BEIJING) fmt.Println("SHANGHAI = ", SHANGHAI) fmt.Println("SHENZHEN = ", SHENZHEN) fmt.Println("a = ", a, "b = ", b) fmt.Println("c = ", c, "d = ", d) fmt.Println("e = ", e, "f = ", f) fmt.Println("g = ", g, "h = ", h) fmt.Println("i = ", i, "k = ", k) // iota 只能夠配合const() 一起使用, iota只有在const進行累加效果。 //var a int = iota }