Golang - 0 not as null

Question

I am passing values to a struct in which the value has omitempty

Offset uint64 'json:"offset,omitempty"'

However when I pass 0 as the value of offset it is also omitted.

Can I somehow declare 0 as a value which is not defined as null?

Answer 1

Structures for serialization often use pointer to indicate a nullable field. It can make working with the structure a little more cumbersome to work with, but has the advantage of discerning between nil and 0

type T struct {
    Offset *uint64 `json:"offset,omitempty"`
}

With a nil pointer

t := T{}
// marshals to "{}"

And after allocating a zero value

t.Offset = new(uint64)
// marshals to `{"offset":0}`