这是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eval. 用例如下：
x作为一个配置对象，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 函数内的内部对象中，这样 x 看起来像：
x={a:1,b:2,music:{shuffle:true}}
我想你可以做这样的事情：
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/
你可以这样做lodash.set()
> l=require('lodash')
> x={a:1,b:2};
{ a: 1, b: 2 }
> l.set(x, 'cd', 3)
{ a: 1, b: 2, c: { d: 3 } }
我相信 dojo 的 setObject 可以满足您的要求。如果您（可以理解）不想引入所有的 dojo，那么我建议您检查他们的（免费提供的）源或通过 AMD 仅加载基本（仅 4k）。它看起来像这样：
function setObject(name, value, context) {
var parts=name.split("."),
p=parts.pop();
for(var i=0, j; context && (j=parts[i]); i++){
context = (j in context ? context[j] : context[j]={});
}
return context && p ? (context[p]=value) : undefined; // Object
}
所以在你的情况下，你会这样做：
x={a:1,b:2};
setObject("c.d", 3, x);
警告：除非您只处理琐碎的案例，否则我会敦促您继续检查完整的 dojo 实现，它处理没有提供上下文等的情况。
这是一个评论较多的版本，应该很容易理解。
// stores the configured data
configStore = {};
config = {
set: function(keyValueString) {
// Split the string by the =
var pair = keyValueString.split('=');
// left of the = is the key path
var keyPath = pair[0];
// right of the = is the value to set
var value = pair[1];
// split keyPath into an array of keys
var keys = keyPath.split('.');
var key; // used in loop
// the current level of object we are drilling into.
// Starts as the main root config object.
var currentObj = configStore;
// Loop through all keys in the key path, except the last one (note the -1).
// This creates the object structure implied by the key path.
// We want to do something different on the last iteration.
for (var i=0; i < keys.length-1; i++) {
// Get the current key we are looping
key = keys[i];
// If the requested level on the current object doesn't exist,
// make a blank object.
if (typeof currentObj[key] === 'undefined') {
currentObj[key] = {};
}
// Set the current object to the next level of the keypath,
// allowing us to drill in.
currentObj = currentObj[key];
}
// Our loop doesn't handle the last key, because that's when we
// want to set the actual value. So find the last key in the path.
var lastKey = keys[keys.length-1]
// Set the property of the deepest object to the value.
currentObj[lastKey] = value;
}
};
// Do it.
config.set('omg.wtf.bbq=123')
// Check it.
alert(configStore.omg.wtf.bbq); // 123
今天不得不做类似的事情，这是另一个解决方案。绝对可以使用一些清理，但它的伎俩。如果输入有效，这将扩展现有对象并且不会擦除任何数据。
没有验证，所以如果你传递了错误的数据，你肯定可以覆盖密钥。
// @param object orig the object to extend
// @param array keyParts the.key.path split by "." (expects an array, presplit)
// @param mixed value the value to assign
// @param object scoped used by the recursion, ignore or pass null
function unflatten(orig, keyParts, value, scoped) {
if (!scoped) {
scoped = orig;
}
var nextKey = keyParts.shift();
if (keyParts.length === 0) {
scoped[nextKey] = value;
return orig;
}
if (!scoped[nextKey]) {
scoped[nextKey] = {};
}
scoped = scoped[nextKey];
return unflatten(orig, keyParts, value, scoped);
}
函数原型可以改进，但可以满足我的需要。通过以下方式调用它：
var orig = { foo: 'hello world', bar: { baz: 'goodbye world' } };
// lets add the key "bar.cat.aww" with value "meow"
unflatten(orig, "bar.cat.aww".split("."), "meow");
/*
orig is {
foo: "hello world",
bar: {
baz: "goodbye world",
cat: {
aww: "meow"
}
}
}
*/
// we can keep calling it to add more keys
unflatten(orig, "some.nested.key".split("."), "weeee");
/*
orig is {
foo: "hello world",
bar: {
baz: "goodbye world",
cat: {
aww: "meow"
}
},
some: {
nested: {
key: "weeee"
}
}
}
*/
这个怎么样？
它将创建或复制/覆盖现有对象。
function expando(obj, base) {
return Object.keys(obj)
.reduce((clone, key) => {
key.split('.').reduce((innerObj, innerKey, i, arr) =>
innerObj[innerKey] = (i+1 === arr.length) ? obj[key] : innerObj[innerKey] || {}, clone)
return clone;
}, Object.assign({}, base));
}
console.log(expando({'a.b': 1})) // { a: { b : 1 }}
console.log(expando({'b.c': 2}, { a: 1 })) // { a: 1, b: { c: 2 }}
console.log(expando({'b.c.d': 2, 'e.f': 3}, { a: 1 })) // { a: 1, b: { c: { d: 2 } }, e: { f: 3}}
注意：箭头函数和Object.assign().
随意玩：
那这个呢 ：
function setObj (str, value, obj) {
var ref = obj, keys = str.split('.');
while (keys.length) {
var currentKey = keys.shift();
ref[currentKey] = keys.length ? (ref[currentKey] ? ref[currentKey] : {}) : value;
ref = ref[currentKey];
}
}
使用输入对象的示例（可能是使用 $.serializeArray 提取的一些表单值）
var serializedInputs = [
{name: 'fruits[1][name]', value: 'Banana'},
{name: 'fruits[1][id]', value: '1'},
{name: 'fruits[2][name]', value: 'Strawberry'},
{name: 'fruits[2][id]', value: '2'},
{name: 'fruits[3][name]', value: 'Raspberry'},
{name: 'fruits[3][id]', value: '3'},
{name: 'fruits[4][name]', value: 'Kiwi'},
{name: 'fruits[4][id]', value: '4'},
{name: 'fruits[5][name]', value: 'Mango'},
{name: 'fruits[5][id]', value: '5'},
{name: 'selected_fruit_id', value: '1'},
]
// This variable holds the result
var obj = {}
serializedInputs.forEach(function(item) {
// Turning square brackets into dot notation
setObj(item.name.replace(/\]/g, '').replace(/\[/g, '.'), item.value, obj);
})
结果
{
"fruits": {
"1": {
"name": "Banana",
"id": "1"
},
"2": {
"name": "Strawberry",
"id": "2"
},
"3": {
"name": "Raspberry",
"id": "3"
},
"4": {
"name": "Kiwi",
"id": "4"
},
"5": {
"name": "Mango",
"id": "5"
}
},
"selected_fruit_id": "1"
}