使用键作为数组类型进行哈希 [英] Hash with key as an array type

问题描述

如何在Go中创建一个数组作为地图。
例如在ruby中我可以实现它：

  quarters = {
 [1，2， 3] => '第一季'，
 [4，5，6] => '第二季'，
 [7,8,9] => '第三季'，
 [10,11,12] => 'fourh quarter'，
} 
 quarters [[1，2，3]] 
＃=> 第一季度
  

如何在高隆看到相同的情况？

Go中的数组类型（不同于切片）是可比较的，所以没有什么神奇的：你可以像任何其他地图一样定义它： map [KeyType] ValueType 其中 KeyType 将为 [3] int 和 ValueType 将字符串。

比较运算符 ==和！=必须完全定义为键类型的操作数;因此，键类型不能是函数，映射或切片。

  m：= map [[3] int] string {} 
 
m [[3] int {1，2，3}] =第一季度
m [[3] int {4,5,6}] =第二季度
m [[3 ] int {7,8,9}] =第三季度
m [[3] int {10，11，12}] =第四季度
 
 fmt.Println ）
  

输出：

 地图[[1 2 3]：第一季度[4 5 6]：第二季度
 [7 8 9]：第三季度[10 11 12]：第四季度] 
  

尝试在

要查询元素：

  fmt.Println（m [[3] int {1，2，3}]）//打印第一季
  

您还可以一步创建地图：

  m：= map [[3 ] int] string {
 [3] int {1，2，3}：第一季，
 [3] int {4,5,6}：第二季，
 [3] int {7,8,9}：第三季度，
 [3] int {10，11，12}： 第四季，
} 
  

How to create a key as array in Go for map. For example in ruby I can implement it such:

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"

How the same will be looked in Golang ?

解决方案

Array types (unlike slices) in Go are comparable, so there is nothing magical in it: you can just define it like any other maps: map[KeyType]ValueType where KeyType will be [3]int and ValueType will be string.

The comparison operators == and != must be fully defined for operands of the key type; thus the key type must not be a function, map, or slice.

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)

Output:

map[[1 2 3]:First quarter [4 5 6]:Second quarter 
    [7 8 9]:Third quarter [10 11 12]:Fourth quarter]

Try it on the Go Playground.

To query an element:

fmt.Println(m[[3]int{1, 2, 3}]) // Prints "First quarter"

You can also create the map in one step:

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",
}

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