如何在Go for map中将键创建为数组。例如在ruby中,我可以这样实现:
quarters = { [1, 2, 3] => 'First quarter', [4, 5, 6] => 'Second quarter', [7, 8 ,9] => 'Third quarter', [10, 11, 12] => 'Fourh quarter', } quarters[[1, 2, 3]] # => "First quarter"
Golang的外观如何?
数组类型(不像片)在Go具有可比性,所以在它什么神奇:你可以定义它像任何其他地图:map[KeyType]ValueType这里KeyType会[3]int和ValueType会string。
map[KeyType]ValueType
KeyType
[3]int
ValueType
string
该比较操作符 ==和=必须为键类型的操作数被完全定义!; 因此,键类型不能为函数,映射或切片。
m := map[[3]int]string{} m[[3]int{1, 2, 3}] = "First quarter" m[[3]int{4, 5, 6}] = "Second quarter" m[[3]int{7, 8, 9}] = "Third quarter" m[[3]int{10, 11, 12}] = "Fourth quarter" fmt.Println(m)
输出:
map[[1 2 3]:First quarter [4 5 6]:Second quarter [7 8 9]:Third quarter [10 11 12]:Fourth quarter]
在Go Playground上尝试一下。
要查询元素:
fmt.Println(m[[3]int{1, 2, 3}]) // Prints "First quarter"
您还可以一步创建地图:
m := map[[3]int]string{ [3]int{1, 2, 3}: "First quarter", [3]int{4, 5, 6}: "Second quarter", [3]int{7, 8, 9}: "Third quarter", [3]int{10, 11, 12}: "Fourth quarter", }