黄桃基础语法:1、iota 用法func main(){ const { a = iota //0 b //1 c= ‘hello’ d //hello e = iota //4 h int32 = 10 } f = iota //0 e = iota //0 fmt.Println(a,b,c,d,e,f)}2、==用法类型不同不能判等 int类型：func main(){ var aa int = 10//等于C的long 可能是 32 和 64 var bb int32 = 10 var cc int64 = 10 if(aa == bb ){//报错 类型必须相同 但是任何 变量都能和未指定类型的常量判等 }}3、:=用法func main(){ a:=1}4、defer 含义1、不管函数异常与否结束时都执行2、defer和顺序有关，一个函数中多个defer，会依次压入栈中，所以执行顺序正好相反3、执行时，函数中所有的代码执行完，再去执行defer，returnpackage mainimport “fmt"func main() { fmt.Println(“main func_b_0: a = “, func_b_0())//10 fmt.Println(“main func_b_1: a = “, func_b_1())//6 fmt.Println(“main func_b_2: a = “, func_b_2())//6 fmt.Println(“main func_b_3: a = “, func_b_3())//6}func func_b_0() (a int) {//必须返回变量a fmt.Println(“func_b_0…top”) a = 5 defer func() { a = 10 fmt.Println(“func_b_0 defer a=”, a)//10 }() a++ fmt.Println(“func_b_0_end a = “, a)//6 return a}func func_b_1() (int) {//返回的类似为int fmt.Println(“func_b_1…top”) a := 5 defer func() { a = 10 fmt.Println(“func_b_1 defer a=”, a)//10 }() a++ fmt.Println(“func_b_1_end a = “, a)//6 return a}func func_b_2() int { fmt.Println(“func_b_2…top”) a := 5 defer func(a *int) { *a = 100 fmt.Println(“func_b_2 defer a=”, *a)//100 }(&a) a++ fmt.Println(“func_b_2_end a = “, a)//6 return a}func func_b_3() int { fmt.Println(“func_b_3…top”) a := 5 defer func(a int) { a = 100 fmt.Println(“func_b_3 defer a=”, a)//100 }(a) a++ fmt.Println(“func_b_3_end a = “, a)//6 return a}func func_b_4() {//输出 3、2、1 defer fmt.Println(“1”) defer fmt.Println(“2”) defer fmt.Println(“3”)}