英文:
What is the advantage of using a pointer to a string instead of a string in Go
问题
这里使用指针的好处是什么？
英文:
Reviewing some go code I came across this:
Person struct {
Name *string `json:"name"`
}
and then some where I saw:
Animal struct {
Name string `json:"name"`
}
What is the advantage of the pointer here?
答案1
得分: 2
*声明了一个指针类型。在解码JSON时，有时会使用指向字符串的指针来区分以下JSON：
JSON Name字段的值
{ } nil
{name: ""} 指向""的指针
如果没有指针，无法区分解码结果中缺失值和空白值。
如果应用程序不需要进行这种区分，那么可以使用问题中显示的第二种形式。这更方便。
英文:
The * declares a pointer type. A pointer to a string is sometimes used when decoding JSON to distinguish the following JSON:
JSON value of the Name field
{ } nil
{name: ""} pointer to ""
Without the pointer, it's not possible to distinguish a missing value from a blank value in the decoded result.
If the application does not need to make this distinction, then use the second form shown in the question. It's more convenient.
答案2
得分: 1
"*" 表示指针。
在你的情况下，Name 是一个指向字符串的指针类型的字段。
请参阅 http://www.golang-book.com/books/intro/8
英文:
* means pointer.
In your case, Name is a field of type pointer to string.
答案3
得分: 1
* 是一个指针。
指针类型表示指向给定类型变量的所有指针的集合，称为指针的基本类型。未初始化指针的值为 nil。
这段内容来自于 Go 语言规范。我建议你阅读全部内容。
英文:
The * is a pointer.
> A pointer type denotes the set of all pointers to variables of a given
> type, called the base type of the pointer. The value of an
> uninitialized pointer is nil.
This is coming from the Go Spec. I would suggest reading it all.
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