golang快速入门-03-golang的常量和iota

　 0　const length int = 10

 1 //const 来定义枚举类型
const (
    //可以在const() 添加一个关键字 iota， 每行的iota都会累加1, 第一行的iota的默认值是0
    BEIJING = iota    //iota = 0
    SHANGHAI          //iota = 1
    SHENZHEN          //iota = 2
)


//const 来定义枚举类型
const (
    //可以在const() 添加一个关键字 iota， 每行的iota都会累加1, 第一行的iota的默认值是0
    BEIJING = 10*iota    //iota = 0
    SHANGHAI          //iota = 10
    SHENZHEN          //iota = 20
)

// 公式继承，直到被覆盖
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
)