A map maps keys to values.
Maps must be created with make (not new) before use; the nil map is empty and cannot be assigned to.
package main import "fmt" type Vertex struct{ Lat, Long float64 } var m map[string]Vertex func main() { m = make(map[string]Vertex) m["Bell Labs"] = Vertex{ 40.68433, -74.39967, } fmt.Println(m["Bell Labs"]) }
原文：http://www.cnblogs.com/ghgyj/p/4055443.html