go 的结构体 不用多说，和c/c++ 类似
可以定义然后直接使用，注意给的实参 用 , 分隔

func main(){fmt.Println("zhangsan ", person{"zhangsan", 22})fmt.Println(newPerson("zhangsan", 22))s := person{name: "lisi", age: 24}fmt.Println(s.name)fmt.Println(s.age)sp := &sfmt.Println("sp: ", sp)dog := struct {name   stringisGood bool}{"Rex",true,}fmt.Println("dog: ", dog)
}// 结构体
type person struct {name stringage  int
}
// 函数封装 实例化
func newPerson(name string, age int) *person {p := person{name: name, age: age}return &p
}

# 运行结果zhangsan  {zhangsan 22}
&{zhangsan 22}
lisi
24
sp:  &{lisi 24}
dog:  {Rex true}

这里涉及到了指针 后面会继续讲解 同时也会和c/c++ 的指针做对比

go 关于 符文的介绍
go strings

func main(){const s = "สวัสดี"fmt.Println("s: ", s, "\nLen:", len(s))for idx, _ := range s {//fmt.Printf("idx: ", idx, "runeValue: ", runeValue)fmt.Printf("idx: %d, s[i]:%x\t", idx, s[idx])}fmt.Println("\nRnu count: ", utf8.RuneCountInString(s))fmt.Println("\n===============")for i, w := 0, 0; i < len(s); i += w {runeValue, width := utf8.DecodeRuneInString(s[i:])fmt.Printf("%#U start at byte position %d\n", runeValue, i)w = widthexamineRune(runeValue)}
}func examineRune(r rune) {if r == 't' {fmt.Println("found tee")} else if r == 'ส' {fmt.Println("found so sua")}
}

# 运行结果
s:  สวัสดี 
Len: 18
idx: 0, s[i]:e0 idx: 3, s[i]:e0 idx: 6, s[i]:e0 idx: 9, s[i]:e0 idx: 12, s[i]:e0        idx: 15, s[i]:e0
Rnu count:  6===============
U+0E2A 'ส' start at byte position 0
found so sua
U+0E27 'ว' start at byte position 3
U+0E31 'ั' start at byte position 6
U+0E2A 'ส' start at byte position 9
found so sua
U+0E14 'ด' start at byte position 12
U+0E35 'ี' start at byte position 15

分析 采用lens(s） 和 utf8.RuneCountInString(s)) 结果不同
前者返回的是 s 的字节长度（字符串的字节数）在utf-8编码下，每个unicode 字符可能由多个字节组成
utf8.RuneCountInString(s)) 返回的是字符串中字符数量。它会将字符串解释为Unicode码点序列，并计算这些码点的数量
%#U c/c++ 的占位符概念也用过来了， 这是用于格式化Unicode 字符，会输出一个完整的Unicode字符的完整描述

go interfaces
需要注意一点，go 的标准封装都是 大写开头

// 需要用到 Pi
import ("math"
)
/*几何 求面积、求周长
*/
type geometry interface {area() float64perim() float64
}type rect struct {width, height float64
}// 结构体  圆的半径
type circle struct {radius float64
}func (r rect) area() float64 {return r.width * r.height
}
func (r rect) perim() float64 {return r.height*2 + r.width*2
}func (c circle) area() float64 {return math.Pi * c.radius * c.radius
}
func (c circle) perim() float64 {return 2 * math.Pi * c.radius
}// 接口
func measure(g geometry) {fmt.Println("g: ", g)fmt.Println("g.area: ", g.area())fmt.Println("g.perim: ", g.perim())
}func main(){
// methodsr := rect{width: 10, height: 5}m2 := circle{radius: 4.44}ans := r.area()fmt.Println("r area: ", ans)tmp := rfmt.Println("tmp perim : ", tmp.perim())r2 := rect{width: 22, height: 33}c2 := circle{radius: 55}measure(r2)measure(c2)measure(m2)
}

# 运行结果
r area:  50
tmp perim :  30
g:  {22 33}
g.area:  726
g.perim:  110
g:  {55}
g.area:  9503.317777109125
g.perim:  345.57519189487726
g:  {4.44}
g.area:  61.93210093580775
g.perim:  27.897342763877365