如何动态添加结构属性以避免冗余代码？ [关闭]

Question

Hi I'm basically struggling to avoid redundancy in my Code.

Here is my Struct:

type Person struct {
    Name   string
    Text   string
    Status string
}

Here is my Func:

func ReworkElementsFromClient(w http.ResponseWriter, r *http.Request){
    var persons []Person
    err := json.NewDecoder(r.Body).Decode(&persons)
    if err != nil {
        http.Error(w, err.Error(), http.StatusBadRequest)
        return
    }

    if len(persons) == 0 {
        err = json.NewEncoder(w).Encode(persons)
        if err != nil {
            http.Error(w, err.Error(), http.StatusInternalServerError)
        }
        return
    }

    persons = append([]Person{persons[0]}, persons...)
    persons = persons[:len(persons)-1]

//Trying to avoid redundancy here 
    persons[0].Name = CreateRandomChars(CreateRandomNumbers(8, 16))
    persons[0].Text = CreateRandomChars(CreateRandomNumbers(8, 16))
    persons[0].Status = CreateRandomChars(CreateRandomNumbers(8, 16))

    err = json.NewEncoder(w).Encode(persons)
        if err != nil {
            http.Error(w, err.Error(), http.StatusInternalServerError)
        }
    return
    }

How to avoid calling each properties at Person[0] to randomizing them?

Answer 1

Without touching reflection, the following code is cleaner and shorter, yet identical to what your code is doing, and can be easily extended for new fields:

c := func() string { return CreateRandomChars(CreateRandomNumbers(8, 16)) }

p := persons[0]
p.Name = c()
p.Text = c()
p.Status = c()

persons = append([]Person{p}, persons[:len(persons)-1]...)

Although I don't really understand why you're duplicating the first slice element and dropping the last. More logical would be to just alter the first element and not drop the last.

A slightly modified version where the utility takes a string pointer could look like this:

c := func(s *string) { *s = CreateRandomChars(CreateRandomNumbers(8, 16)) }

p := persons[0]
c(&p.Name)
c(&p.Text)
c(&p.Status)

persons = append([]Person{p}, persons[:len(persons)-1]...)

This pointer version can also be simplified further if the number of fields grows, as you can pass them using a for loop:

c := func(s *string) { *s = CreateRandomChars(CreateRandomNumbers(8, 16)) }

p := persons[0]
for _, s := range []*string{&p.Name, &p.Text, &p.Status} {
    c(s)
}

persons = append([]Person{p}, persons[:len(persons)-1]...)

And now that we're referring to the c() function variable only once, we can even leave it out entirely:

p := persons[0]
for _, s := range []*string{&p.Name, &p.Text, &p.Status} {
    *s = CreateRandomChars(CreateRandomNumbers(8, 16))
}

persons = append([]Person{p}, persons[:len(persons)-1]...)