Example
A value of a struct type can be written using a struct literal that specifies values for its fields.
type Point struct { X, Y int }
p := Point{1, 2}
The above example specifies every field in the right order. Which is not useful, because programmers have to remember the exact fields in order. More often, a struct can be initialized by listing some or all of the field names and their corresponding values.
anim := gif.GIF{LoopCount: nframes}
Omitted fields are set to the zero value for its type.
Note: The two forms cannot be mixed in the same literal.
