golang 括号用法总结

func add(x,y int) (int,error){
  return x+y, nil
}

type Person struct {
  Name string
}

func (p *Person) String() string{
  return p.Name
}

i:=1*(2+3)

a:=int(100)

d:=time.Duration(1 * time.Second)

func output(x interface{}) {
	v, ok := x.(string)
	if ok {
		print(v)
	}
}

type User struct{}

func (u *User) Show() {
	fmt.Println("hello. buddy")
}

func main() {
	(&User{}).Show()  // 这里
}

import (
	"fmt"
	"time"
)

var (
	a = 1
	b = 2
)

const (
	c = 3
	d = 4
)

func main() {

	parts := []int{1, 2, 3}
	arr := [3]int{1, 2, 3}
	m := map[string]string{"a": "b", "c": "d"}

}

func main(){
	for {
		// statment
    switch i{
    case 1:
      // statement
    default:
     	// statement
    }
	}
}

fun main(){
  i:=3
  {
    i:=3
    // statement
  }
}

	m := map[string]string{"a": "b", "c": "d"}

	arr1 := [3]int{1, 2, 3}
	arr2 := [...]int{1, 2, 3, 4, 5}

nums := []int{1, 2, 3}

	a := m["a"]
	n1 := arr2[0]
	n2 := nums[1]

package main

import "fmt"

func main() {
	add(1,2)
	add("a","b")
	// add[int]("a","b") // 错误， 强制约束了传入为 int 类型
}


type Addable interface {
	type int,string
}

func add[T Addable](a,b T) {  
	fmt.Println(a+b)
}