Golang in cannot use * * (Type interface {}) as type * * solution

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When you take a value from the session in Beego, it is intergace{}, but the value I return first is int, or string, and this time an error occurs:
cannot use ** （变量）(type interface {}) as type **（类型）

Error code:

func CurrentId(ctx *context.Context) int {    userStr := ctx.Input.CruSession.Get("user_id")    return userStr}

A type is removed from the session and interface cannot be converted directly, and I give the user_id the int type when assigning to the value.
Therefore, the USERSTR can be converted directly.

The correct code is as follows:

func CurrentId(ctx *context.Context) int {    userStr := ctx.Input.CruSession.Get("user_id")    return userStr.(int)}