转到：如何检查struct属性是否显式设置为零值？

type Animal struct {
    Name string
    LegCount int
}

snake := Animal{Name: "snake", LegCount: 0}
worm := Animal{Name: "worm"}

Question: How can I check snake and worm after they've been set, to tell that:

1. snake was explicitly set with a LegCount of 0.
2. The worm's LegCount was not explicitly set (and therefore based off of its default value)?

It is simply impossible to distinguish.

If you are unmarshalling data from XML or JSON, use pointers.

type Animal struct {
    Name *string
    LegCount *int
}

You will get nil values for absent fields.

You can use the same convention in your case.