Golang - Comparison operator not defined on interface converted to float64

As shown in the code below, I'm doing some type switching on an interface{} in order to do the correct type switching - I'm trying to convert the interface{} to either a float64 or a string and then comparing it to a value, however, when using a comparison operator other than == on the float64's, Go complains about it when building.

The errors Go spits out are as follows :-

invalid operation: (interface {})(val.(float64)) > subval.Value (operator > not defined on interface)
invalid operation: (interface {})(val.(float64)) >= subval.Value (operator >= not defined on interface)
invalid operation: (interface {})(val.(float64)) < subval.Value (operator < not defined on interface)
invalid operation: (interface {})(val.(float64)) <= subval.Value (operator <= not defined on interface)

...and this is my code:-

val:= s.FieldByName(subval.Metric).Interface()
switch val(type) {
case float64, float32, int:
	switch subval.Type {
	case "greater_than":
		if val.(float64) > subval.Value {
			runAction(subval.Action, Config)
		}
	case "greater_than_or_equal_to":
		if val.(float64) >= subval.Value {
			runAction(subval.Action, Config)
		}
	case "equal_to":
		if val.(float64) == subval.Value {
			runAction(subval.Action, Config)
		}
	case "less_than":
		if val.(float64) < subval.Value {
			runAction(subval.Action, Config)
		}
	case "less_than_or_equal_to":
		if val.(float64) <= subval.Value {
			runAction(subval.Action, Config)
		}
	}
case string:
	if subval.Type == "equal_to" {
		if val.(string) == subval.Value {
			runAction(subval.Action, Config)
		}
	}
}

Your problem is probably that subval.Value is an interface{}, so the comparison operator isn't available. I think that when doing an equality comparison with an interface, go compare the underlying types byte-wise, hence the == not giving an error.

If someone got here like me, then for him I will describe my situation like this. Let it be here

I had a similar problem. It was necessary to compare the two ints that the List container returns as interfaces.

I solved it this way:

1. Initialized the variable
2. Assigned it a value that I return using fmt.Sprint() - this function returns the passed value as a string to your variable.
3. Then I converted the string to the type I needed
4. And so I was able to compare these values

For example:

list1.Front().Value > list2.Front().Value // i cant compare it because this 
                                         //  method returns inerfase{}
value1 := fmt.Sprint(list1.Front().Value) // so if you do it this way
value2 := fmt.Sprint(list2.Front().Value) 


// ...CONVERTING TO int's USING func Atoi()
// you can compare these two values
isItTrue := value1 > value2