golang omitempty的用法-ag真人官方网

omitempty作用是在json数据结构转换时，当该字段的值为该字段类型的零值时，忽略该字段。

package main
import (
	"fmt"
	"encoding/json"
)
type student struct {
	name string `json:"name"`
	age int  `json:"age"`
	grade  string `json:"grade,omitempty"`
}
func main() {
	stu1 := student{
		name:"tom",
		age:18,
		grade:"middle school",
	}
	stu2  := student{
		name:"lily",
		age:19,
	}
	stubyts1,_ := json.marshal(&stu1)
	stubyts2 ,_ := json.marshal(&stu2)
	fmt.println("stu1:",string(stubyts1))
	fmt.println("stu2:",string(stubyts2))
}

打印结果如下：
stu1: {"name":"tom","age":18,"grade":"middle school"}
stu2: {"name":"lily","age":19}