Question

我有一个javascript对象，我将其用作具有键值对的地图类型。

当从控制器注入值时，会发生此映射的填充：

var people = {"2":"Brad","3":"Antonio","5":"Stacy","6":"Marry","1":"Jim"}

我想创建一个新对象但是还有一个条目，即伪代码

var new_people = people + {11: "John"}

我首先尝试将人们复制给新人：

new_people.\"11\" = "John"

和

new_people."11" = "John"

两者都会产生失败。虽然任何字符串而不是数字，但

new_people.anystring = "John"

var new_people = {"2":"Brad","3":"Antonio","5":"Stacy","6":"Marry","1":"Jim", "anystring":"John"}

Answer 1

您可以使用索引：

new_people['11'] = 'John';

Answer 2

您只需要为对象添加键值：

people['11'] = "John";

如果密钥是有效的标识符名称（不是数字），您可以使用它：

people.key = "John";

当索引不是有效的变量名时，必须使用索引：

people["~!#$#$#HV"] ="some value";

Answer 3

您将遇到问题，因为变量在存储对象时会保留引用。通过改变new_people，你也在改变人们。

var people = {"1":"James"}
console.log(people);       // Object {1: "James"}
var new_people = people;
new_people["2"] = "Jimmy";
console.log(people);       // Object {1: "James", 2: "Jimmy"}
console.log(new_people);   // Object {1: "James", 2: "Jimmy"}

您需要首先克隆对象，然后改变克隆，以免影响原始对象。

一种简单的方法是使用underscore.js extend（）方法，如下所示：

var new_people = _.extend({}, people, {"2": "Jimmy"});
console.log(people);       // Object {1: "James"}
console.log(new_people);   // Object {1: "James", 2: "Jimmy"}

或类似地，使用jQuery extend（），如下所示：

var new_people = $.extend({}, people, {"2": "Jimmy"});
console.log(people);       // Object {1: "James"}
console.log(new_people);   // Object {1: "James", 2: "Jimmy"}

Answer 4

@Gandalf StormCrow这是一段代码：jsfiddle

var people = {"2":"Brad","3":"Antonio","5":"Stacy","6":"Marry","1":"Jim"};

var newpeople = {"11": "John"};
jQuery.extend(people, newpeople);
//Now: people = {"2":"Brad","3":"Antonio","5":"Stacy","6":"Marry","1":"Jim","11": "John"}

for(var i in people){
  alert(people[i]);  
};

向对象添加新属性

4 个答案: