How to get zero value of a field type

Question

I have a struct containing many fields - I\'ve figured out how to extract the field name, value, and tag information using reflection. What I also want to do is to determine if

Answer 1

You can switch on the Kind() of the Value and use the appropriate accessor (many fewer kinds than types). Something like:

switch valueField.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
    if valueField.Int() == 0 {...}
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
    if valueField.Uint() == 0 {...}
case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
    if valueField.IsNil() {...}
//add more cases for Float, Bool, String, etc (and anything else listed http://golang.org/pkg/reflect/#Kind )
}

You could also get a zeroed instance of a value by using reflect.Zero(valueField.Type()) but it is not safe to compare that with valueField since some types (such as slices and maps) do not support equality and would panic.