The struct structure of Go language

struct structure

• The struct in Go is very similar to the struct in C, and go has no class
• Define structure using type<name> struct{}, name follows visibility rules
• Supports pointer-type members pointing to themselves
• Supports anonymous structures that can be used as members or define member variables
• Anonymous structures can also be used for map values
• Structure can be initialized with literal values
• Allows you to read and write struct members directly through pointers
• Members of the same type can make direct copy assignment
• The = = and! = Comparison operators are supported, but not > or <
• Support for anonymous fields, essentially a field defined by a type name
• Embedded structure as anonymous field looks like inheritance, but not inherited
• You can use the anonymous field pointer

Test Cases

//package mainimport "fmt"//定义了一 个空的结构体type st01 struct {}//定义一个非空的结构体type person struct {    Name string    Age  int}func main() {    personInfo := person{}    personInfo.Age = 19    personInfo.Name = "xiaoqiang"    fmt.Println(personInfo)    //------------------------------    fmt.Println("=============================")    //直接初始化   属于 字面值 初始化    personInfo2 := person{Name :"spark01", Age: 19}    fmt.Println(personInfo2)}

struct, passed by value

 

//结构体，按值 传递package mainimport "fmt"//定义一个类型type sparkInfo struct {    SparkClusterName string    SparkNodeNum     int}func main() {    newSparkInfo := sparkInfo{        SparkNodeNum:     8,        SparkClusterName: "spark-test-001"}    fmt.Println("main:\t", newSparkInfo)    updateSparkInfo(newSparkInfo)    fmt.Println("main:\t", newSparkInfo)}//同样，这里是值传递，内部的修改，并不会影响到 旧值的func updateSparkInfo(sparkInfo sparkInfo) {    sparkInfo.SparkNodeNum = 9    fmt.Println("updateSparkInfo:\t", sparkInfo)}

Structure, passing by address

 

//结构体，按地址传递package mainimport "fmt"type k8sInfo struct {    K8sClusterName string //k8s集群的名称    K8sClusterNumm int    //k8s集群的节点个数}func main() {    k8sInfo := k8sInfo{        K8sClusterNumm: 1,        K8sClusterName: "k8s-test-001"}    fmt.Println(k8sInfo)    updateK8sClusterInfo(&k8sInfo)    fmt.Println(k8sInfo)}//传递的是 地址，按地址传递//修改了，旧的值func updateK8sClusterInfo(info *k8sInfo) {    info.K8sClusterNumm = 110    fmt.Println("updateK8s:\t", info)}

Structure, passing by address

 

//结构体，按地址传递package mainimport "fmt"type dockerInfo struct {    DockerClusterName string    DockerClusterNum int}func main() {    //一般更习惯这种写法，    //在初始化的时候，就直接获取地址    //这样以后在调用的时候，就不需要添加&号了    dInfo := &dockerInfo{        DockerClusterNum:19,        DockerClusterName:"docker-yizhuang"}    fmt.Println("init docker:\t", dInfo)    updateDockerInfo(dInfo)    fmt.Println("after docker:\t", *dInfo)}func updateDockerInfo (info *dockerInfo) {    info.DockerClusterNum = 80    fmt.Println("udpateDocker:\t", info)}

Anonymous structure

 

//匿名结构package mainimport "fmt"func main() {    //创建一个匿名结构，    //并且进行了初始化    //而且，直接获取地址&    ftp := &struct {        FtpName string        FtpNum int    }{        FtpName:"ftp-beijing",        FtpNum:8}    fmt.Println(ftp)    fmt.Println(*ftp)    fmt.Println("FtpName:\t", ftp.FtpName)    fmt.Println("FtpNum:\t", ftp.FtpNum)}

Anonymous structure, nested into other structures

 

//将匿名结构，嵌套进别的结构体里package mainimport "fmt"type hadoop struct {    HadoopClusterName string    HadoopClusterNum  int    //创建一个匿名结构    HadoopOtherInfo struct {        //同样，当多个变量都一样的时候，也可用省略        //这是Go语言的优点        HadoopVersion, HadoopUrl string    }}func main() {    hdfs := &hadoop{        HadoopClusterName: "Hadoop-test-001",        HadoopClusterNum:  9}    //只能通过这种方式，进行初始化    hdfs.HadoopOtherInfo.HadoopUrl = "http://192.168.1.110:50070"    hdfs.HadoopOtherInfo.HadoopVersion = "v2.7.0"    fmt.Println(hdfs)    fmt.Println(*hdfs)    fmt.Println("HadoopClusterName:\t", hdfs.HadoopClusterName)    fmt.Println("HadoopClusterNum:\t", hdfs.HadoopClusterNum)    fmt.Println("HadoopClusterVersion:\t", hdfs.HadoopOtherInfo.HadoopVersion)    fmt.Println("HadoopClusterUrl:\t", hdfs.HadoopOtherInfo.HadoopUrl)}

Anonymous fields

 

//匿名字段  测试package mainimport "fmt"type students struct {    //这些就是匿名字段，没有定义名字    string    int}func main() {    boy := &students{        //初始化的时候，必须按照顺序来进行的        "xiaoqiang", 19}    fmt.Println(boy)}

Operations between identical structures, such as assignment, comparison

 

// 相同结构体  之间 操作，如赋值，比较package mainimport "fmt"type teacherA struct {    string    int} type teacherB struct {    string    int }func main() {    boyTeacherA := teacherA{"xiaoli",22}    //boyTeacherB := teacherB{"xiaoli",22}    //説明：编译报错了，teacherA, teacherB  类型不相同，不能进行比较的    //fmt.Println(boyTeacherA == boyTeacherB)    boyTeacherB := teacherA{"xiaoli", 23}    fmt.Println(boyTeacherB == boyTeacherA)}

struct, implementing an effect similar to inheritance

 

//结构体，实现 类似于 继承的效果package mainimport "fmt"type anminal struct {    //设置一些共有的属性    Name, address string}type cat struct {    //anminal  Go 语言，默认，anminal是类型，同时也是属性名称    anminal    Sex int         // 猫的特有属性，性别是啥}type dog struct {    anminal    Hobby string  //狗的特有属性，爱好}func main() {    //第一种初始化方式    xiaoCat := cat{Sex:0, anminal : anminal{Name:"xiaohong", address:"beijing"}}    xiaoDog := dog{Hobby:"play", anminal:anminal{Name:"xiaohuang", address:"shanghai"}}    //第二种初始化方式    xiaoCat.anminal.Name = "xiaoxiaoxiaohong" //这种方式，是为了防止名字相同时，冲突    xiaoCat.Name = "xiaoxiaohong"    fmt.Println("cat:\t", xiaoCat)    fmt.Println("dog:\t",xiaoDog)}

The struct structure of Go language