英文:
How do you access certain parts of an array with type []interface{} in Go?
问题
我有一个包含字符串键和不同类型值的映射，打印出来的样子是这样的：
map[command:ls count:[1 1]]
当对 count 使用 reflect.TypeOf 进行检查时，返回的类型是 []interface{}。我无法通过索引访问这些值，如果我尝试将其传递给一个接受 []interface{} 类型参数的函数，它会报告我试图传递一个类型为 interface{} 的值。
我想在这个例子中访问 count，它应该有两个值，即 1 和 1。
英文:
I have a map with string keys and different types for values, when printing it looks like this:
map[command:ls count:[1 1]]
When checking reflect.TypeOf on the count it returns type []interface{}. I cannot access the values by index, and if I try passing it into a function that accept a param of type []interface{} it claims that I'm tying to pass a value of type interface{}
I would like to access the count in this example which would be 2 values. 1 and 1.
答案1
得分: 6
你需要区分类型和底层类型。你的映射类型是 map[string]interface{}。这意味着 count 的值是 interface{} 类型，其底层类型是 []interface{}。因此，你不能将 count 作为 []interface{} 类型传递。在使用它作为数组之前，你需要进行类型断言。每个项目的类型将是 interface{}，可以进一步断言为 int（根据你的数据似乎是这样）。
示例：
count := m["count"].([]interface{})
value1 := count[0].(int)
value2 := count[1].(int)
英文:
You have to differentiate type and underlying type. Your map is of the type map[string]interface{}. Which means that the value for count is of type interface{}, and its underlying type if []interface{}. So you can't pass the count as a type []interface{}. You have do a type assertion it before using it as an array. Every item will then of type interface{}, which can in turn be asserted as int (as it seem your data is).
Example:
count := m["count"].([]interface{})
value1 := count[0].(int)
value2 := count[1].(int)
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