Go - Functions - 2

• Modifications to the parameter copy don't affect the caller except pointer, slice, map, function, channel
  
• A function declaration without a body indicate that the function is implemented in a language other than Go
• A function can have multiple return values, client can assign return value to a blank identifier to ignore
• Ex. data, _ = findData()
• Function can be assigned to variable
Ex. func a(){}; func b(){}; f=a; f(); f+b; f()
Ex. func d(s string) {}; f=d; // compile error

• Zero value of function is nil
• Can use == to compare function (can only check is function nil), but function is not comparable so can not be key in map