go 指针接收者和值接收者的区别小结

package main

import "fmt"

type coder interface {
    code()
    debug()
}

type Gopher struct {
    language string
}

func (p Gopher) code() {
    fmt.Printf("I am coding %s language\n", p.language)
}

func (p *Gopher) debug() {
    fmt.Printf("I am debuging %s language\n", p.language)
}

func main() {
    var c coder = &Gopher{"Go"} //运行正常
    //上一行换成： var c coder = Gopher{"Go"} 
    // 则报错 Gopher does not implement coder (debug method has pointer receiver)
    c.code()
    c.debug()
}

package main

import "fmt"

type Node struct {
    val int
}

func (receiver Node) changeVal1() {
    receiver.val++
}

func (receiver *Node) changeVal2() {
    receiver.val++
}
func main() {
    someOne := Node{}
    someOne.changeVal1()
    fmt.Printf("%d\n", someOne.val) //0 ，说明没有改值，因为方法接收者是值接收者

    someOnePtr := &Node{}
    someOnePtr.changeVal1()
    fmt.Printf("%d\n", someOnePtr.val) //0 ，说明没有改值，因为方法接收者是值接收者，与调用方是否指针无关

    someTwo := Node{}
    someTwo.changeVal2()
    fmt.Printf("%d\n", someTwo.val) //1 ，说明成功改值，因为方法接收者是指针接收者，与调用方是否指针无关

    someTwoPtr := &Node{}
    someTwoPtr.changeVal2()
    fmt.Printf("%d\n", someTwoPtr.val) //1 ，说明成功改值，因为方法接收者是指针接收者，与调用方是否指针无关

}