在eval反序列化后,Javascript原型未定义

Cub*_*ass 5 javascript json prototype eval

尝试反序列化JSON数据并更新每个对象的原型并继承常用函数.

但是,以下脚本抛出错误"people [0] .getFullName不是函数".分配后,反序列化对象的原型似乎未定义.

<html>
<head>
<script>
var json = '[ {"firstName": "John", "lastName": "Smith"}, {"firstName": "Nancy", "lastName": "Jones"} ]';
var people;
eval('people = ' + json);

function Person() { }

Person.prototype.getFullName = function() {
    return this.firstName + ' ' + this.lastName;
}

//assign prototype
for(var i=0; i < people.length; i++){
    people[i].prototype = new Person();
}


if(people[0].getFullName() !== 'John Smith')
    alert('Expected fullname to be John Smith but was ' + people[0].getFullName());
</script>
</head>
</html>
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mol*_*olf 2

该属性是构造函数prototype的属性,而不是实例的属性。您正在寻找的是以下房产:__proto__

people[i].__proto__ = new Person();
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坏消息是它并不适用于所有浏览器。它在 Firefox 和 Safari 中工作,但在 IE 中不起作用。另一种方法是使用构造函数来实例化您的人员数组。不幸的是,您必须复制所有属性:

function Person(obj) {
    for (var property in obj) {
        this[property] = obj[property];
    }
    return this;
}
Person.prototype.getFullName = function() {
    return this.firstName + ' ' + this.lastName;
}

var people;
eval('people = ' + json);
for(var i=0; i < people.length; i++) {
    people[i] = new Person(people[i]);
}
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