go语言实现接口查询_Golang_

 package options type IPeople interface { GetName() string } type IPeople2 interface { GetName() string GetAge() int } package main import ( "fmt" "options" ) type person struct { name string } func (p *person) GetName() string { return p.name } type person2 struct { name string age int } func (p *person2) GetName() string { return p.name } func (p *person2) GetAge() int { return p.age } func main() { //p不可以转化为options.IPeople2接口，没有实现options.IPeople2接口中的GetAge() var p options.IPeople = &person{"jack"} if p2, ok := p.(options.IPeople2); ok { fmt.Println(p2.GetName(), p2.GetAge()) } else { fmt.Println("p不是Ipeople2接口类型") } //p2可以转化为options.IPeople接口，因为实现了options.IPeople接口的所有方法 var p2 options.IPeople2 = &person2{"mary", 23} if p, ok := p2.(options.IPeople); ok { fmt.Println(p.GetName()) } var pp options.IPeople = &person{"alen"} if pp2, ok := pp.(*person); ok { fmt.Println(pp2.GetName()) //pp接口指向的对象实例是否是*person类型,*不能忘 } switch pp.(type) { case options.IPeople: fmt.Println("options.IPeople") //判断接口的类型 case options.IPeople2: fmt.Println("options.IPeople2") default: fmt.Println("can't found") } var ii interface{} = 43 //默认int类型 switch ii.(type) { case int: fmt.Println("int") default: fmt.Println("can't found") } }

 var v1 interface{} = 1 var v2 interface{} = "abc" var v3 interface{} = 2.345 var v4 interface{} = make(map[..]...) ....

 package main import "fmt" //空接口可以接受任何值 //interface { } func main() { var v1 interface{ } v1 = 6.78 //赋值一个变量v判断其类型是否为float64，是则为真，否则，为假 if v, ok := v1.(float64);ok{ fmt.Println(v, ok) }else { fmt.Println(v,ok) } }

 package main import "fmt" //空接口可以接受任何值 //interface { } func main() { var v1 interface{ } v1 = "张三" switch v1.(type) { case float32: case float64: fmt.Println("this is float64 type") case string: fmt.Println("this is string type") } }