import
import unuse package:
error : imported and not used: "os"
:= =
c := 1 // error non-declaration statement outside function body
d = 1 // error non-declaration statement outside function body
func test(){
c = 1 //undefined: should be c:=1
//d = 1
var f , d int
f,d = cal()
fmt.Println(c, f, d)
}
right using value declare and use
package main
import "fmt"
//var a := 0 //wrong
var a int = 0
//c := 1 //wrong
//d = 1 //wrong
func cal(b int)(val1 int, val2 int){
fmt.Println(b)
val1 = 1
val2 = 2
return
}
func test(){
c := 1
//d = 1 //wrong
var f , d int
f,d = cal(1)
fmt.Println(c, f, d)
}
func main() {
fmt.Println("Hello, world var")
}
declear not use
./right.go:14: c declared and not used
type struct init using () ,instead of {} ,which {} is the right usage
type Response struct {
Code string `json:"code"`
Body string `json:"body"`
}
//not like this ()
//Response("OK", "ECHO: " + method + " ~ " + params)
//right usage {}
Response{"OK", "ECHO: " + method + " ~ " + params}
如何理解以下代码：
type IpcClient struct {
conn chan string
}
func (client *IpcClient)Call(method, params string)(resp *Response, err error){
}
- (client *IpcClient) -- 调用的对象要是 IpcClient struct
- (method, params string) -- 参数，前面是参数名，后面是参数类型，两种同类别省略写法。
- (resp *Response, err error) 参数返回值，返回值的第一个参数，类型为 Response struct 对象指针, 返回值的第二个参数，类型为 error 类型,