如何从json获取具有动态变量的对象值

Question

我希望从JSON获取对象字段的值。我有一个动态变量let check_permission_key = 'ratingscalename';并且有一个JSON

let overwrite_key = {
  studentimage: 'student',
  ratingscalename: 'rating-scale-name',
  ratingscale: 'rating-scale-name',
  capturesettingset: 'capture-setting-set',
  capturesetting: 'capture-setting-set',
  eventlog: 'event-log',
  goalcategorie: 'goal-category',
  userimage: 'user',
  datasheetlink: 'datasheet',
  datasheetgoal: 'datasheet',
};

let get_value = overwrite_key.check_permission_key;

所以我是这样获取数据的，但是没有用，有人能帮我解决这个问题吗？

Answer 1

若要使用变量访问对象属性值，请使用括号([])符号

​

let overwrite_key = {'studentimage':'student','ratingscalename':'rating-scale-name','ratingscale':'rating-scale-name','capturesettingset':'capture-setting-set','capturesetting':'capture-setting-set','eventlog':'event-log','goalcategorie':'goal-category','userimage':'user','datasheetlink':'datasheet','datasheetgoal':'datasheet'};
let check_permission_key = 'ratingscalename';
let get_value = overwrite_key[check_permission_key];
console.log(get_value);

​

Answer 2

javascript中的对象基本上是带有字符串键的数组，因此您可以访问如下所示的动态属性：

let get_value = overwrite_key[check_permission_key];

Answer 3

您可以使用eval()函数。

​

let overwrite_key = {
  studentimage: 'student',
  ratingscalename: 'rating-scale-name',
  ratingscale: 'rating-scale-name',
  capturesettingset: 'capture-setting-set',
  capturesetting: 'capture-setting-set',
  eventlog: 'event-log',
  goalcategorie: 'goal-category',
  userimage: 'user',
  datasheetlink: 'datasheet',
  datasheetgoal: 'datasheet',
};
let check_permission_key = 'ratingscalename';
let get_value = eval(`overwrite_key.${check_permission_key}`);
console.log(get_value);

​

JavaScript eval()函数