var  变量名 变量类型

var name string
var age int
var isOK bool

var (
  name string
  age     int
  isOK    bool
)

var 变量名 类型 = 表达式(值)

var name string = "junming.zhai"
var age  int = 18

var name,age = "junming.zhai",18

package main
import (
    "fmt"
)

//全局变量
var m = 100


func main(){
    name := "junming.zhai"  //段变量,只能在函数内部用
    age  := 18
    fmt.Println(name,age)
}

package main
import (
    "fmt"
)

//foo函数会有两个值
func foo() (int, string) {
    return 10, "junming.zhai"
}

func main() {
    age, _ := foo()   //foo函数会有两个值,需要用两个变量接收,但是这里直用一个参数接收,另一个参数用下划线"_"代替,就是没有参数接收
    _, name := foo()
    fmt.Println(age)
    fmt.Println(name)
}

结果:

10
junming.zhai

const 常量名 = 值

const name = junming.zhai

const (
  name = "junming.zhai"
  age = 18
)