用点表示法创建一个对象

Question

这是对这个问题的反向问题.

给定一个对象x={a:1,b:2}和一个字符串c.d=3,将对象x修改为以下内容:

{
  a:1,
  b:2,
  c:{
    d:3
  }
}

我正在寻找一种不使用的解决方案eval.用例如下:

x 作为配置对象,我们称之为: config.set("music.shuffle",true)

现在,music.shuffle必须以某种方式解析并添加到xconfig.set函数内的内部对象,以便x看起来像:

x={a:1,b:2,music:{shuffle:true}}

Answer 1

在我的脑海中,我猜你可以这样做:

function addValueToObj(obj, newProp) {
    newProp = newProp.split("=");       // separate the "path" from the "value"

    var path = newProp[0].split("."),     // separate each step in the "path"
        val = newProp.slice(1).join("="); // allow for "=" in "value"

    for (var i = 0, tmp = obj; i < path.length - 1; i++) {
       tmp = tmp[path[i]] = {};     // loop through each part of the path adding to obj
    }
    tmp[path[i]] = val;             // at the end of the chain add the value in
}

var x = {a:1, b:2};
addValueToObj(x, "c.d=3");
// x is now {"a":1,"b":2,"c":{"d":"3"}}
addValueToObj(x, "e.f.g.h=9=9");
// x is now {"a":1,"b":2,"c":{"d":"3"},"e":{"f":{"g":{"h":"9=9"}}}}

演示:http://jsfiddle.net/E8dMF/1/

Answer 2

你可以这样做 lodash.set()

> l=require('lodash')
> x={a:1,b:2};
{ a: 1, b: 2 }
> l.set(x, 'c.d', 3)
{ a: 1, b: 2, c: { d: 3 } }