go中空接口的具体使用

type empty_iface interface {
}

package main

import "fmt"

type empty_interface interface{
}

func main() {
	var e empty_interface
	fmt.Println(e)
	fmt.Printf("type: %T, value: %v", e, e)
}T, value: %v", i, i)
}

package main

import (
    "fmt"
)

func main()  {
    // 声明一个空接口实例
    var i interface{}

    // 存 int 没有问题
    i = 1
    fmt.Printf("type: %T, value: %v\n", i, i)

    // 存字符串也没有问题
    i = "hello"
    fmt.Printf("type: %T, value: %v\n", i, i)

    // 存布尔值也没有问题
    i = false
    fmt.Printf("type: %T, value: %v\n", i, i)
}

package main

import (
    "fmt"
)

func myfunc(iface interface{}){
    fmt.Println(iface)
}

func main()  {
    a := 10
    b := "hello"
    c := true

    myfunc(a)
    myfunc(b)
    myfunc(c)
}

package main

import (
    "fmt"
)

func myfunc(ifaces ...interface{}){
    for _,iface := range ifaces{
        fmt.Printf("type: %T, value: %v\n", iface, iface)
    }
}

func main()  {
    a := 10
    b := "hello"
    c := true

    myfunc(a, b, c)
}

package main

import "fmt"

func main() {
    any := make([]interface{}, 5)
    any[0] = 11
    any[1] = "hello world"
    any[2] = []int{11, 22, 33, 44}
    for i, value := range any {
        fmt.Printf("arr[%d]:\nType: %T, Value: %v\n", i,value, value)
    }
}

package main

func main() {
    // 声明a变量, 类型int, 初始值为1
    var a int = 1

    // 声明i变量, 类型为interface{}, 初始值为a, 此时i的值变为1
    var i interface{} = a

    // 声明b变量, 尝试赋值i
    var b int = i
}

package main

import "fmt"

func main() {
    sli := []int{2, 3, 5, 7, 11, 13}
	// 空接口承载切片
    var i interface{}
    i = sli
	// 再用切片生成切片
    g := i[1:3]
    fmt.Println(g)
}

package main

import (
    "fmt"
)

func myfunc(i interface{})  {

    switch x:=i.(type) {
    case int:
        fmt.Printf("参数的值为：%v，参数的类型是 int\n",x)
    case string:
        fmt.Printf("参数的值为：%v，参数的类型是 string\n",x)
    }
}

func main() {
    a := 10
    b := "hello"
    myfunc(a)
    myfunc(b)
}