Go - Structs - 3

• A struct can be declared to require client need assign values to each fields with right order. 
  Such pattern will be hard to maintain in the future because client code need to be changed when ordering changed.
  Suitable use case: Point{x,y} or RGB{r,g,b}
  
  
• A struct can be declared by specifying variable name. If variable name is omitted, zero value will be set.
  
• Struct values can be passed to a functions and return from them
  
• If struct is big, can be passed through pointer
• Go is call-by-value