> ### for 和 for range區別 * range 可以將每個獨立的Unicode碼點分離出來 ~~~ package main import ( "fmt" "time" "reflect" ) type student struct { name string age int content string } func main() { //for range只能用于遍歷系統自帶的array slice map 和chan ,數據結構就不能用range s1 := student{name: "張三", age: 18, content: "Hello World"} for k := 0; k < reflect.TypeOf(s1).NumField(); k++ { fmt.Println(reflect.TypeOf(s1).Field(k).Name, "=>", reflect.ValueOf(s1).Field(k)) } number1 := []int{4, 8, 12, 16, 20} //len := len(number1) 用變量代替, 不用每次循環都計算number1長度 for i := 0; i < len(number1); i++ { if i == 0 { number1 = append(number1, 24) } fmt.Print(&number1[i], " - ") } fmt.Println("") number2 := []int{4, 8, 12, 16, 20} //range是申請一個地址n，并且把值拷貝到&n for k, v := range number2 { if k == 0 { number2 = append(number2, 24) } fmt.Print(&v, " - ") } fmt.Println("") number3 := []int{4, 8, 12, 16, 20} for _, v := range number3 { go func() { fmt.Print(v, "-") }() } time.Sleep(time.Second) } ~~~