Go语言 接口

• 

  接口

  Go编程语言提供了另一种称为接口(interface)的数据类型，它表示一组方法签名。struct数据类型将这些接口实现为具有接口的方法签名的方法定义。

  语法

  
  /* 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 */
  }
  

• 

  示例

  
  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))
  }
  

  尝试一下

  编译并执行上述代码后，将产生以下结果-

  
  Circle area: 78.539816
  Rectangle area: 50.000000