在范围功能中按地址查询

Question

I have a OuterStruct structure defined as given below. I am using the function to initialize the OuterStruct -> InnerStruct values Name and Var1 in setup1() and Var1 in setup2().

The value assigned in setup2() is nil always because it is referring it by value. How to use refer my address here ?

type InnerStruct struct {
    Name  string
    Var1  *api.Var1
    Var2  *ap1.Var2
}

type OuterStruct struct {
    opName   string
    MyData   []InnerStruct
    LogDir   string
}

func (obj *OuterStruct) Setup2() {
    for _, innerObj := range obj.InnerStruct {   // Here is the prob becuase of using refer by value
        innerObj.Var2 = callToPopulateValue()
    }
}

func Setup1() {
    innerStructList := []InnerStruct

    myStruct := InnerStruct{}
    myStruct.Name = "name1"
    myStruct.Var1 = callToPopulateValue()
    innerStructList = append(innerStructList, myStruct)

    finalStruct = &OuterStruct {
        opName: "structName",
        MyData: innerStructList,
        LogDir: "/path/for/my/logs",
    }

    finalStruct.Setup2()
}

Answer 1

You can't access by address, but you can get the index from range instead, and assign to the slice directly:

    for i := range obj.MyData {
        obj.MyData[i].Var2 = callToPopulateValue()
    }

Alternately, you can just use a slice of pointer values:

type OuterStruct struct {
    opName   string
    MyDAta   []*InnerStruct
    LogDir   string
}

func (obj *OuterStruct) Setup2() {
    for _, innerObj := range obj.MyData {
        innerObj.Var2 = callToPopulateValue()
    }
}