动态更新/创建对象属性 [英] Update/Create object properties dynamically

问题描述

我正在创建一个提供get（）和set（）函数的功能，以便从JavaScript对象中读取和更新值。诀窍是我使用带点标记的字符串来指定属性。

I'm creating a feature that provides a get() and set() function to read and update values from a JavaScript object. The trick is that I'm using a dot notated string to specify the properties.

我的get（）工作正常，它是我的set（）我遇到了麻烦。

I've got the get() working fine, it's the set() that I'm having troubles with.

示例数据：

var data = {
    person: {
        name: 'Fred',
        birthday: '19840101',
        address: {
            street: '123 Main St.',
            city: 'Anytown',
            state: 'NY',
            zip: '123123'
        },
        family: {
            spouse: 'Sally',
            children: ['Sam', 'Frank', 'Susan']
        }
    }
};

get（）函数：

function get (path) {
    var parts = path.split('.'),
        tmp = data;
    for (var i = 0, l = parts.length; i < l; ++i) {
        if (tmp[parts[i]]) {
            tmp = tmp[parts[i]];
        }
        else {
            tmp = null
            break;
        }
    }
    return tmp;
}

console.log(get('person.name')); // Fred
console.log(get('person.family.children')); // ['Sam', 'Frank', 'Susan']
console.log(get('person.jobs.apple')); // null

set（）函数：

var foo = null;
function set (path, val) {
    var parts = path.split('.')
        tmp = {},
        foo = data;

    for (var i = 0, l = parts.length; i < l; ++i) {
        if (tmp[parts[i]]) {
            tmp = data[parts[i]];
        }
        else {
            tmp = {};
        }
        if (i+1 === l) {
            tmp = val;
        }
        data[parts[i]] = tmp;
    }
}

set('person.name', 'Dave'); // replace existing name
set('person.family.children', ['Tim', 'Matt', 'Kathy']); // replace existing array
set('person.jobs.apple', 'developer'); // should create the necessary properties
console.log(data);

我最终得到以下物品：

obj = {
    person: {},
    name: "Dave",
    family: {},
    children: ["Tim","Matt","Kathy"],
    jobs: {},
    apple: "developer"
}

关于如何做到这一点的任何想法？

Any thoughts on how to accomplish this?

推荐答案

你没有真的需要任何功能。

You do not really need any functions at all for this.

看到这个

var data = {
    person: {
        name: 'Fred',
        birthday: '19840101',
        address: {
            street: '123 Main St.',
            city: 'Anytown',
            state: 'NY',
            zip: '123123'
        },
        family: {
            spouse: 'Sally',
            children: ['Sam', 'Frank', 'Susan']
        }
    }
};

alert(data.person.name);
data['person']['name'] = 'Tim';
alert(data['person']['name']);

还有这个答案可能会有所帮助

There is also this answer which may help

Javascript对象键值编码。动态设置嵌套值

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