动态设置嵌套对象的属性

Question

我有一个对象，它可以是任意多个级别的深度，并且可以具有任何现有属性。例如：

var obj = {

    db: {

        mongodb: {

            host: 'localhost'

        }

    }

};

在此我想设置（或覆盖）属性，如下所示：

set('db.mongodb.user', 'root');

// or:

set('foo.bar', 'baz');

属性字符串可以具有任何深度，并且值可以是任何类型/事物。

如果属性键已经存在，则不需要合并对象和数组作为值。

前面的示例将产生以下对象：

var obj = {

    db: {

        mongodb: {

            host: 'localhost',

            user: 'root'

        }

    },

    foo: {

        bar: baz

    }

};

如何实现这种功能？

Answer 1

使用您指定的参数，此函数应添加/更新obj容器中的数据。请注意，您需要跟踪obj架构中的哪些元素是容器，哪些是值（字符串，整数等），否则您将开始引发异常。obj = {};&nbsp; // global objectfunction set(path, value) {&nbsp; &nbsp; var schema = obj;&nbsp; // a moving reference to internal objects within obj&nbsp; &nbsp; var pList = path.split('.');&nbsp; &nbsp; var len = pList.length;&nbsp; &nbsp; for(var i = 0; i < len-1; i++) {&nbsp; &nbsp; &nbsp; &nbsp; var elem = pList[i];&nbsp; &nbsp; &nbsp; &nbsp; if( !schema[elem] ) schema[elem] = {}&nbsp; &nbsp; &nbsp; &nbsp; schema = schema[elem];&nbsp; &nbsp; }&nbsp; &nbsp; schema[pList[len-1]] = value;}set('mongo.db.user', 'root');

Answer 2

有点晚了，但这是一个非图书馆的，更简单的答案：/**&nbsp;* Dynamically sets a deeply nested value in an object.&nbsp;* Optionally "bores" a path to it if its undefined.&nbsp;* @function&nbsp;* @param {!object} obj&nbsp; - The object which contains the value you want to change/set.&nbsp;* @param {!array} path&nbsp; - The array representation of path to the value you want to change/set.&nbsp;* @param {!mixed} value - The value you want to set it to.&nbsp;* @param {boolean} setrecursively - If true, will set value of non-existing path as well.&nbsp;*/function setDeep(obj, path, value, setrecursively = false) {&nbsp; &nbsp; let level = 0;&nbsp; &nbsp; path.reduce((a, b)=>{&nbsp; &nbsp; &nbsp; &nbsp; level++;&nbsp; &nbsp; &nbsp; &nbsp; if (setrecursively && typeof a[b] === "undefined" && level !== path.length){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; a[b] = {};&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return a[b];&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; if (level === path.length){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; a[b] = value;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return value;&nbsp; &nbsp; &nbsp; &nbsp; } else {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return a[b];&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }, obj);}我做的这个功能可以完全满足您的需求。假设我们要更改深嵌套在此对象中的目标值：let myObj = {&nbsp; &nbsp; level1: {&nbsp; &nbsp; &nbsp; &nbsp; level2: {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;target: 1&nbsp; &nbsp; &nbsp; &nbsp;}&nbsp; &nbsp; }}因此，我们将这样调用函数：setDeep(myObj, ["level1", "level2", "target1"], 3);将导致：myObj = {级别1：{级别2：{目标：3}}}将set递归设置为true将设置对象（如果不存在）。setDeep(myObj, ["new", "path", "target"], 3);将导致：obj = myObj = {&nbsp; &nbsp; new: {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;path: {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;target: 3&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;}&nbsp; &nbsp; },&nbsp; &nbsp; level1: {&nbsp; &nbsp; &nbsp; &nbsp; level2: {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;target: 3&nbsp; &nbsp; &nbsp; &nbsp;}&nbsp; &nbsp; }}

Answer 3

受其他伙伴的启发：function leaf(obj, path, value) {  const pList = path.split('.');  const key = pList.pop();  const pointer = pList.reduce((accumulator, currentValue) => {    if (accumulator[currentValue] === undefined) accumulator[currentValue] = {};    return accumulator[currentValue];  }, obj);  pointer[key] = value;  return obj;}例：const obj = {  boats: {    m1: 'lady blue'  }};leaf(obj, 'boats.m1', 'lady blue II');leaf(obj, 'boats.m2', 'lady bird');console.log(obj); // { boats: { m1: 'lady blue II', m2: 'lady bird' } }