How to Safely Convert an interface{} Value to an int in Go?

Type Assertions for Interface{} Value Conversions to Int

Converting an interface{} value to int can cause errors if not performed correctly. A type assertion is necessary for this conversion.

Error Explanation

The error message suggests that you cannot convert the interface{} value directly to int because there needs to be a type assertion.

Code Examination

In your code:

    val, ok := m["area_id"]
    if !ok {
        utility.CreateErrorResponse(w, "Error: Area ID is missing from submitted data.")
        return
    }

    fmt.Fprintf(w, "Type = %v", val)   // <--- Type = float64
    iAreaId := int(val)                // <--- Error on this line.

The issue lies in this line:

    iAreaId := int(val)

Solution

Instead of directly converting the value, you need to use a type assertion. It checks if the value can be converted to int and throws an error if not. There are two ways to do this:

// Panicking version
iAreaId := val.(int)

// Non-panicking version
iAreaId, ok := val.(int)
if !ok {
    // Handle the error case here
}

By making this change, you can successfully convert the interface{} value to int and continue with your code's execution.

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