在Go中使用指向字符串的指针而不是字符串的好处是什么[重复]

Question

This question already has an answer here:

• What does the asterisk do in “Go” 6 answers

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?

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Answer 1

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.