Go – structure

Time:2021-2-21

summary

A structure is an aggregate data type that combines zero or more variables of any type. It can also be regarded as a collection of data.
Declaration structure

 

//demo_11.go    
    package main    
    import (    
        "fmt"    
    )    
    type Person struct {    
        Name string    
        Age int    
    }    
    func main() {    
        var p1 Person    
        p1.Name = "Tom"    
        p1.Age  = 30    
        fmt.Println("p1 =", p1)    
        var p2 = Person{Name:"Burke", Age:31}    
        fmt.Println("p2 =", p2)    
        p3 := Person{Name:"Aaron", Age:32}    
        fmt.Println("p2 =", p3)    
        //Anonymous structure    
        p4 := struct {    
            Name string    
            Age int    
        }{Name: "anonymous,", Age:33 }    
        fmt.Println("p4 =", p4)    
    }

 

Results of operation:

Generating JSON

   

//demo_12.go    
    package main    
    import (    
        "encoding/json"    
        "fmt"    
    )    
    type Result struct {    
        Code    int    `json:"code"`    
        Message string `json:"msg"`    
    }    
    func main() {    
        var res Result    
        res.Code    = 200    
        res.Message = "success"    
        //Serialization    
        jsons, errs := json.Marshal(res)    
        if errs != nil {    
            fmt.Println("json marshal error:", errs)    
        }    
        fmt.Println("json data :", string(jsons))    
        //Deserialization    
        var res2 Result    
        errs = json.Unmarshal(jsons, &res2)    
        if errs != nil {    
            fmt.Println("json unmarshal error:", errs)    
        }    
        fmt.Println("res2 :", res2)    
    }

 

Results of operation:


Changing data

 

  //demo_13.go    
    package main    
    import (    
        "encoding/json"    
        "fmt"    
    )    
    type Result struct {    
        Code    int    `json:"code"`    
        Message string `json:"msg"`    
    }    
    func main() {    
        var res Result    
        res.Code    = 200    
        res.Message = "success"    
        toJson(&res)    
        setData(&res)    
        toJson(&res)    
    }    
    func setData (res *Result) {    
        res.Code    = 500    
        res.Message = "fail"    
    }    
    func toJson (res *Result) {    
        jsons, errs := json.Marshal(res)    
        if errs != nil {    
            fmt.Println("json marshal error:", errs)    
        }    
        fmt.Println("json data :", string(jsons))    
    }

 

Results of operation: