如何从使用interface {}输入的golang map [string]字符串中提取值？

Question

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I have something like this:

x1 := someFunctionWithAnInterfaceReturnValue()

and the underlying type is something like this:

x2 := map[string] string{"hello": "world"}

How would I access value in x1?

Essentially I want the equivalent of this for x1:

 var value string = x2["hello"]

</div>

Answer 1

Use a type assertion:

x1 := someFunctionWithAnInterfaceReturnValue()
x2, ok := x1.(map[string]string)
if !ok {
   // handle unexpected type
}
var value string = x2["hello"]