Go编程提供了另一种称为接口(interfaces
)的数据类型,它代表一组方法签名。struct
数据类型实现这些接口以具有接口的方法签名的方法定义。
/* define an interface */ type interface_name interface { method_name1 [return_type] method_name2 [return_type] method_name3 [return_type] ... method_namen [return_type] } /* define a struct */ type struct_name struct { /* variables */ } /* implement interface methods*/ func (struct_name_variable struct_name) method_name1() [return_type] { /* method implementation */ } ... func (struct_name_variable struct_name) method_namen() [return_type] { /* method implementation */ }
package main import ( "fmt" "math" ) /* define an interface */ type Shape interface { area() float64 } /* define a circle */ type Circle struct { x,y,radius float64 } /* define a rectangle */ type Rectangle struct { width, height float64 } /* define a method for circle (implementation of Shape.area())*/ func(circle Circle) area() float64 { return math.Pi * circle.radius * circle.radius } /* define a method for rectangle (implementation of Shape.area())*/ func(rect Rectangle) area() float64 { return rect.width * rect.height } /* define a method for shape */ func getArea(shape Shape) float64 { return shape.area() } func main() { circle := Circle{x:0,y:0,radius:5} rectangle := Rectangle {width:10, height:5} fmt.Printf("Circle area: %f\n",getArea(circle)) fmt.Printf("Rectangle area: %f\n",getArea(rectangle)) }
当上述代码编译和执行时,它产生以下结果:
Circle area: 78.539816 Rectangle area: 50.000000