golang-結構體的使用

package main

import (
    "fmt"
    "unsafe"
)

type Person struct {
    name string
    sex byte
    age int
}

type Student struct {
    p []Person
    id []int
    score [1000]int
}

func test(man Person)  {
    fmt.Println("test temp size:", unsafe.Sizeof(man))

    man.name = "name1"
    man.age = 33

    fmt.Println("test: man", man)
}

func main()  {
    // 1. 順序初始化, 必須全部初始化完整
    var man Person = Person{"andy", 'm', 18}
    fmt.Println("man:", man)

    // 2. 部分初始化
    man2 := Person{sex:'f', age:19}
    fmt.Println("man2:", man2)
    // 索引成員變量 “.”
    fmt.Printf("man2.name = %q\n", man2.name)

    var man3 Person
    man3.name = "mike"
    man3.sex = 'm'
    man3.age = 99
    fmt.Println("man3:", man3)
    man3.age = 1073
    fmt.Println("man3:", man3)

    // 結構體比較
    var p1 Person = Person{"andy", 'm', 18}
    var p2 Person = Person{"andy", 'm', 18}
    var p3 Person = Person{"andy", 'm', 181}

    fmt.Println("p1 == p2 ?", p1 == p2)
    fmt.Println("p1 == p3 ?", p1 == p3)

    // 相同類型結構體賦值
    var tmp Person
    fmt.Println("tmp", tmp)
    tmp = p3
    fmt.Println("tmp", tmp)

    // 函數內部使用結構體傳參
    var temp Person
    fmt.Println("main temp size:", unsafe.Sizeof(temp))
    test(temp)                    // 值傳遞。將實參的值拷貝一份給形參。
    fmt.Println("temp", temp)

    fmt.Printf("&tmp = %p\n", &temp)
    fmt.Printf("&temp.name = %p\n", &(temp.name))

    fmt.Println("main temp size:", unsafe.Sizeof(true))  // 1 /0
}