动态设置嵌套对象的属性

此函数应使用您指定的参数添加/更新obj容器中的数据。 请注意，您需要跟踪架构obj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 = {};  // global object
function set(path, value) {
    var schema = obj;  // a moving reference to internal objects within obj
    var pList = path.split('.');
    var len = pList.length;
    for(var i = 0; i < len-1; i++) {
        var elem = pList[i];
        if( !schema[elem] ) schema[elem] = {}
        schema = schema[elem];
    }
    schema[pList[len-1]] = value;
}
set('mongo.db.user', 'root');

Lodash 有一个 _.set（） 方法。

_.set(obj, 'db.mongodb.user', 'root');
_.set(obj, 'foo.bar', 'baz');

我只是使用 ES6 + 递归编写一个小函数来实现目标。

updateObjProp = (obj, value, propPath) => {
    const [head, ...rest] = propPath.split('.');
    !rest.length
        ? obj[head] = value
        : this.updateObjProp(obj[head], value, rest.join('.'));
}
const user = {profile: {name: 'foo'}};
updateObjProp(user, 'fooChanged', 'profile.name');

我在反应更新状态时经常使用它，它对我来说效果很好。

有点晚了，但这里有一个非库的，更简单的答案：

/**
 * Dynamically sets a deeply nested value in an object.
 * Optionally "bores" a path to it if its undefined.
 * @function
 * @param {!object} obj  - The object which contains the value you want to change/set.
 * @param {!array} path  - The array representation of path to the value you want to change/set.
 * @param {!mixed} value - The value you want to set it to.
 * @param {boolean} setrecursively - If true, will set value of non-existing path as well.
 */
function setDeep(obj, path, value, setrecursively = false) {
    path.reduce((a, b, level) => {
        if (setrecursively && typeof a[b] === "undefined" && level !== path.length){
            a[b] = {};
            return a[b];
        }
        if (level === path.length){
            a[b] = value;
            return value;
        } 
        return a[b];
    }, obj);
}

我做的这个功能可以完全满足你的需要，甚至更多。

假设我们要更改深度嵌套在此对象中的目标值：

let myObj = {
    level1: {
        level2: {
           target: 1
       }
    }
}

因此，我们将像这样调用我们的函数：

setDeep(myObj, ["level1", "level2", "target1"], 3);

将导致：

myObj = { 级别 1：{ 级别 2：{ 目标：3 } } }

将 set 递归标志设置为 true 将设置对象（如果它们不存在）。

setDeep(myObj, ["new", "path", "target"], 3, true);

将导致：

obj = myObj = {
    new: {
         path: {
             target: 3
         }
    },
    level1: {
        level2: {
           target: 3
       }
    }
}

我们可以使用递归函数：

/**
 * Sets a value of nested key string descriptor inside a Object.
 * It changes the passed object.
 * Ex:
 *    let obj = {a: {b:{c:'initial'}}}
 *    setNestedKey(obj, ['a', 'b', 'c'], 'changed-value')
 *    assert(obj === {a: {b:{c:'changed-value'}}})
 *
 * @param {[Object]} obj   Object to set the nested key
 * @param {[Array]} path  An array to describe the path(Ex: ['a', 'b', 'c'])
 * @param {[Object]} value Any value
 */
export const setNestedKey = (obj, path, value) => {
  if (path.length === 1) {
    obj[path] = value
    return
  }
  return setNestedKey(obj[path[0]], path.slice(1), value)
}

更简单！

灵感来自@bpmason1的回答：

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;
}
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' } }

ES6 也有一个非常酷的方法可以使用计算属性名称和Rest 参数来做到这一点。

const obj = {
  levelOne: {
    levelTwo: {
      levelThree: "Set this one!"
    }
  }
}
const updatedObj = {
  ...obj,
  levelOne: {
    ...obj.levelOne,
    levelTwo: {
      ...obj.levelOne.levelTwo,
      levelThree: "I am now updated!"
    }
  }
}

如果levelThree是一个动态属性，即在levelTwo中设置任何属性，则可以使用 [propertyName]: "I am now updated!" 其中propertyName在levelTwo中保存属性的名称。

我想出了自己的解决方案，使用纯 es6 和不改变原始对象的递归。

const setNestedProp = (obj = {}, [first, ...rest] , value) => ({
  ...obj,
  [first]: rest.length
    ? setNestedProp(obj[first], rest, value)
    : value
});
const result = setNestedProp({}, ["first", "second", "a"], 
"foo");
const result2 = setNestedProp(result, ["first", "second", "b"], "bar");
console.log(result);
console.log(result2);

Lodash 有一个名为 update 的方法，它完全可以满足您的需求。

此方法接收以下参数：

1. 要更新的对象
2. 要更新的属性的路径（属性可以深度嵌套）
3. 返回要更新的值的函数（给定原始值作为参数）

在您的示例中，它看起来像这样：

_.update(obj, 'db.mongodb.user', function(originalValue) {
  return 'root'
})

我需要实现同样的事情，但在 Node.js...所以，我找到了这个不错的模块：https://www.npmjs.com/package/nested-property

例：

var mod = require("nested-property");
var obj = {
  a: {
    b: {
      c: {
        d: 5
      }
    }
  }
};
console.log(mod.get(obj, "a.b.c.d"));
mod.set(obj, "a.b.c.d", 6);
console.log(mod.get(obj, "a.b.c.d"));

我创建了要点，用于根据正确答案按字符串设置和获取 obj 值。您可以下载它或将其用作 npm/yarn 包。

// yarn add gist:5ceba1081bbf0162b98860b34a511a92
// npm install gist:5ceba1081bbf0162b98860b34a511a92
export const DeepObject = {
  set: setDeep,
  get: getDeep
};
// https://stackoverflow.com/a/6491621
function getDeep(obj: Object, path: string) {
  path = path.replace(/'[('w+)']/g, '.$1'); // convert indexes to properties
  path = path.replace(/^'./, '');           // strip a leading dot
  const a = path.split('.');
  for (let i = 0, l = a.length; i < l; ++i) {
    const n = a[i];
    if (n in obj) {
      obj = obj[n];
    } else {
      return;
    }
  }
  return obj;
}
// https://stackoverflow.com/a/18937118
function setDeep(obj: Object, path: string, value: any) {
  let schema = obj;  // a moving reference to internal objects within obj
  const pList = path.split('.');
  const len = pList.length;
  for (let i = 0; i < len - 1; i++) {
    const elem = pList[i];
    if (!schema[elem]) {
      schema[elem] = {};
    }
    schema = schema[elem];
  }
  schema[pList[len - 1]] = value;
}
// Usage
// import {DeepObject} from 'somePath'
//
// const obj = {
//   a: 4,
//   b: {
//     c: {
//       d: 2
//     }
//   }
// };
//
// DeepObject.set(obj, 'b.c.d', 10); // sets obj.b.c.d to 10
// console.log(DeepObject.get(obj, 'b.c.d')); // returns 10

扩展@bpmason1提供的接受答案，以支持字符串路径中的数组，例如字符串路径可以'db.mongodb.users[0].name'和'db.mongodb.users[1].name'。

它将设置属性值，如果不存在，则将创建该值。

var obj = {};
function set(path, value) {
  var schema = obj;
  var keysList = path.split('.');
  var len = keysList.length;
  for (var i = 0; i < len - 1; i++) {
    var key = keysList[i];
    // checking if key represents an array element e.g. users[0]
    if (key.includes('[')) {
      //getting propertyName 'users' form key 'users[0]'
      var propertyName = key.substr(0, key.length - key.substr(key.indexOf("["), key.length - key.indexOf("[")).length);
      if (!schema[propertyName]) {
        schema[propertyName] = [];
      }
      // schema['users'][getting index 0 from 'users[0]']
      if (!schema[propertyName][parseInt(key.substr(key.indexOf("[") + 1, key.indexOf("]") - key.indexOf("[") - 1))]) {
        // if it doesn't exist create and initialise it
        schema = schema[propertyName][parseInt(key.substr(key.indexOf("[") + 1, key.indexOf("]") - key.indexOf("[") - 1))] = {};
      } else {
        schema = schema[propertyName][parseInt(key.substr(key.indexOf("[") + 1, key.indexOf("]") - key.indexOf("[") - 1))];
      }
      continue;
    }
    if (!schema[key]) {
      schema[key] = {};
    }
    schema = schema[key];
  } //loop ends
  // if last key is array element
  if (keysList[len - 1].includes('[')) {
    //getting propertyName 'users' form key 'users[0]'
    var propertyName = keysList[len - 1].substr(0, keysList[len - 1].length - keysList[len - 1].substr(keysList[len - 1].indexOf("["), keysList[len - 1].length - keysList[len - 1].indexOf("[")).length);
    if (!schema[propertyName]) {
      schema[propertyName] = [];
    }
    // schema[users][0] = value;
    schema[propertyName][parseInt(keysList[len - 1].substr(keysList[len - 1].indexOf("[") + 1, keysList[len - 1].indexOf("]") - keysList[len - 1].indexOf("[") - 1))] = value;
  } else {
    schema[keysList[len - 1]] = value;
  }
}
// will create if not exist
set("mongo.db.users[0].name.firstname", "hii0");
set("mongo.db.users[1].name.firstname", "hii1");
set("mongo.db.users[2].name", {
  "firstname": "hii2"
});
set("mongo.db.other", "xx");
console.log(obj);
// will set if exist
set("mongo.db.other", "yy");
console.log(obj);

下面是使用 ES 12 的解决方案

function set(obj = {}, key, val) {
  const keys = key.split('.')
  const last = keys.pop()
  keys.reduce((o, k) => o[k] ??= {}, obj)[last] = val
}

（对于旧版本的javascript，您可以在reduce中执行o[k] || o[k] = {}操作）

首先，我们将keys设置为除最后一个键之外的所有内容的数组。

然后在化简中，累加器更深入地进入obj每次，如果未定义该键处的值，则将其初始化为空对象。

最后，我们将最后一个键的值设置为 val .

如果只需要更改更深的嵌套对象，则另一种方法是引用该对象。由于 JS 对象由其引用处理，因此您可以创建对具有字符串键访问权限的对象的引用。

例：

// The object we want to modify:
var obj = {
    db: {
        mongodb: {
            host: 'localhost',
            user: 'root'
        }
    },
    foo: {
        bar: baz
    }
};
var key1 = 'mongodb';
var key2 = 'host';
var myRef = obj.db[key1]; //this creates a reference to obj.db['mongodb']
myRef[key2] = 'my new string';
// The object now looks like:
var obj = {
    db: {
        mongodb: {
            host: 'my new string',
            user: 'root'
        }
    },
    foo: {
        bar: baz
    }
};

另一种方法是使用递归来挖掘对象：

(function(root){
  function NestedSetterAndGetter(){
    function setValueByArray(obj, parts, value){
      if(!parts){
        throw 'No parts array passed in';
      }
      if(parts.length === 0){
        throw 'parts should never have a length of 0';
      }
      if(parts.length === 1){
        obj[parts[0]] = value;
      } else {
        var next = parts.shift();
        if(!obj[next]){
          obj[next] = {};
        }
        setValueByArray(obj[next], parts, value);
      }
    }
    function getValueByArray(obj, parts, value){
      if(!parts) {
        return null;
      }
      if(parts.length === 1){
        return obj[parts[0]];
      } else {
        var next = parts.shift();
        if(!obj[next]){
          return null;
        }
        return getValueByArray(obj[next], parts, value);
      }
    }
    this.set = function(obj, path, value) {
      setValueByArray(obj, path.split('.'), value);
    };
    this.get = function(obj, path){
      return getValueByArray(obj, path.split('.'));
    };
  }
  root.NestedSetterAndGetter = NestedSetterAndGetter;
})(this);
var setter = new this.NestedSetterAndGetter();
var o = {};
setter.set(o, 'a.b.c', 'apple');
console.log(o); //=> { a: { b: { c: 'apple'}}}
var z = { a: { b: { c: { d: 'test' } } } };
setter.set(z, 'a.b.c', {dd: 'zzz'}); 
console.log(JSON.stringify(z)); //=> {"a":{"b":{"c":{"dd":"zzz"}}}}
console.log(JSON.stringify(setter.get(z, 'a.b.c'))); //=> {"dd":"zzz"}
console.log(JSON.stringify(setter.get(z, 'a.b'))); //=> {"c":{"dd":"zzz"}}

晚了 - 这是一个香草 js 函数，它接受路径作为参数并返回修改后的对象/JSON

let orig_json = {
  string: "Hi",
  number: 0,
  boolean: false,
  object: {
    subString: "Hello",
    subNumber: 1,
    subBoolean: true,
    subObject: {
      subSubString: "Hello World"
    },
    subArray: ["-1", "-2", "-3"]
  },
  array: ["1", "2", "3"]
}
function changeValue(obj_path, value, json) {
  let keys = obj_path.split(".")
  let obj = { ...json },
    tmpobj = {},
    prevobj = {}
  for (let x = keys.length - 1; x >= 0; x--) {
    if (x == 0) {
      obj[keys[0]] = tmpobj
    } else {
      let toeval = 'json.' + keys.slice(0, x).join('.');
      prevobj = { ...tmpobj
      }
      tmpobj = eval(toeval);
      if (x == keys.length - 1) tmpobj[keys[x]] = value
      else {
        tmpobj[keys[x]] = prevobj
      }
    }
  }
  return obj
}
let newjson = changeValue("object.subObject.subSubString", "Goodbye world", orig_json);
console.log(newjson)

添加或覆盖属性的另一种解决方案：

function propertySetter(property, value) {
  const sampleObject = {
    string: "Hi",
    number: 0,
    boolean: false,
    object: {
      subString: "Hello",
      subNumber: 1,
      subBoolean: true,
      subObject: {
        subSubString: "Hello World",
      },
      subArray: ["-1", "-2", "-3"],
    },
    array: ["1", "2", "3"],
  };
  const keys = property.split(".");
  const propertyName = keys.pop();
  let propertyParent = sampleObject;
  while (keys.length > 0) {
    const key = keys.shift();
    if (!(key in propertyParent)) {
      propertyParent[key] = {};
    }
    propertyParent = propertyParent[key];
  }
  propertyParent[propertyName] = value;
  return sampleObject;
}
console.log(propertySetter("object.subObject.anotherSubString", "Hello you"));
console.log(propertySetter("object.subObject.subSubString", "Hello Earth"));
console.log(propertySetter("object.subObject.nextSubString.subSubSubString", "Helloooo"));

灵感来自不可变的 JS setIn 方法，该方法永远不会改变原始方法。这适用于混合数组和对象嵌套值。

function setIn(obj = {}, [prop, ...rest], value) {
    const newObj = Array.isArray(obj) ? [...obj] : {...obj};
    newObj[prop] = rest.length ? setIn(obj[prop], rest, value) : value;
    return newObj;
}
var obj = {
  a: {
    b: {
      c: [
        {d: 5}
      ]
    }
  }
};
const newObj = setIn(obj, ["a", "b", "c", 0, "x"], "new");
//obj === {a: {b: {c: [{d: 5}]}}}
//newObj === {a: {b: {c: [{d: 5, x: "new"}]}}}

@aheuermann sed，您可以使用lodash库中的set，

但是，如果出于某种原因不想向项目添加lodash，则可以使用递归函数来设置/覆盖对象中的值。

/**
 * recursion function that called in main function 
 * @param obj initial JSON
 * @param keysList array of keys
 * @param value value that you want to set
 * @returns final JSON
 */
function recursionSet(obj, keysList, value) {
    const key = keysList[0]
    if (keysList.length === 1) return { ...obj, [key]: value }
    return { ...obj, [key]: (recursionSet(obj?.[key] || {}, keysList.slice(1), value)) }
}
/**
 * main function that you can call for set a value in an object by nested keys
 * @param obj initial JSON
 * @param keysString nested keys that seprated by "."
 * @param value value that you want to set
 * @returns final JSON
 */
function objectSet(obj, keysString, value) {
    return recursionSet(obj, keysString.split('.'), value)
}
// simple usage
const a1 = {}
console.log('simple usage:', objectSet(a1, "b.c.d", 5))
// keep the initial data
const a2 = {b:{e: 8}}
console.log('keep the initial data:', objectSet(a2, "b.c.d", 5))
// override data
const a3 = {b:{e: 8, c:2}}
console.log('override data:', objectSet(a3, "b.c.d", 5))
// complex value
const a4 = {b:{e: 8, c:2}}
console.log('complex value:', objectSet(a4, "b.c.d", {f:12}))

如果你想要一个需要先验属性存在的函数，那么你可以使用这样的东西，它还会返回一个标志，说明它是否设法找到并设置了嵌套属性。

function set(obj, path, value) {
    var parts = (path || '').split('.');
    // using 'every' so we can return a flag stating whether we managed to set the value.
    return parts.every((p, i) => {
        if (!obj) return false; // cancel early as we havent found a nested prop.
        if (i === parts.length - 1){ // we're at the final part of the path.
            obj[parts[i]] = value;          
        }else{
            obj = obj[parts[i]]; // overwrite the functions reference of the object with the nested one.            
        }   
        return true;        
    });
}

JQuery 有一个扩展方法：

https://api.jquery.com/jquery.extend/

只需将覆盖作为对象传递，它就会合并两者。

灵感来自 ClojureScript 的 assoc-in （https://github.com/clojure/clojurescript/blob/master/src/main/cljs/cljs/core.cljs#L5280），使用递归：

/**
 * Associate value (v) in object/array (m) at key/index (k).
 * If m is falsy, use new object.
 * Returns the updated object/array.
 */
function assoc(m, k, v) {
    m = (m || {});
    m[k] = v;
    return m;
}
/**
 * Associate value (v) in nested object/array (m) using sequence of keys (ks)
 * to identify the path to the nested key/index.
 * If one of the values in the nested object/array doesn't exist, it adds
 * a new object.
 */
function assoc_in(m={}, [k, ...ks], v) {
    return ks.length ? assoc(m, k, assoc_in(m[k], ks, v)) : assoc(m, k, v);
}
/**
 * Associate value (v) in nested object/array (m) using key string notation (s)
 * (e.g. "k1.k2").
 */
function set(m, s, v) {
    ks = s.split(".");
    return assoc_in(m, ks, v);
}

注意：

通过提供的实现，

assoc_in({"a": 1}, ["a", "b"], 2) 

返回

{"a": 1}

我希望它在这种情况下抛出错误。如果需要，可以添加签入assoc以验证m是对象还是数组，否则将引发错误。

简而言之，我尝试编写此集合方法，它可能会对某人有所帮助！

function set(obj, key, value) {
 let keys = key.split('.');
 if(keys.length<2){ obj[key] = value; return obj; }
 let lastKey = keys.pop();
 let fun = `obj.${keys.join('.')} = {${lastKey}: '${value}'};`;
 return new Function(fun)();
}
var obj = {
"hello": {
    "world": "test"
}
};
set(obj, "hello.world", 'test updated'); 
console.log(obj);
set(obj, "hello.world.again", 'hello again'); 
console.log(obj);
set(obj, "hello.world.again.onece_again", 'hello once again');
console.log(obj);

const set = (o, path, value) => {
    const props = path.split('.');
    const prop = props.shift()
    if (props.length === 0) {
        o[prop] = value
    } else {
        o[prop] = o[prop] ?? {}
        set(o[prop], props.join('.'), value)
    }
}

如果您想深入更新或插入对象试试这个：-

 let init = {
       abc: {
           c: {1: 2, 3: 5, 0: {l: 3}},
           d: 100
       }
    }
    Object.prototype.deepUpdate = function(update){
       let key = Object.keys(update);
       key.forEach((k) => {
           if(typeof update[key] == "object"){
              this[k].deepUpdate(update[key], this[k])
           }
           else 
           this[k] = update[k]
       })
    }
    init.deepUpdate({abc: {c: {l: 10}}})
    console.log(init)

但是要确保它会更改原始对象，您可以使其不更改原始对象：

JSON.parse(JSON.stringify(init)).deepUpdate({abc: {c: {l: 10}}})

改进 bpmason1 的答案：-添加一个 get（） 函数。-不需要定义全局存储对象- 它可以从同一域iFrame访问

function set(path, value) 
{
  var schema = parent.document;
  path="data."+path;
  var pList = path.split('.');
  var len = pList.length;
  for(var i = 0; i < len-1; i++) 
  {
    if(!schema[pList[i]]) 
      schema[pList[i]] = {}
    schema = schema[pList[i]];
  }
  schema[pList[len-1]] = value;
}
function get(path) 
{
  path="data."+path;
  var schema=parent.document;
  var pList = path.split('.');
  for(var i = 0; i < pList.length; i++) 
    schema = schema[pList[i]];
  return schema;
}
set('mongo.db.user', 'root');
set('mongo.db.name', 'glen');
console.log(get('mongo.db.name'));  //prints 'glen'

有时，如果键也有点 （.） 它的字符串，这可能会带来问题。因为即使是那个键现在也会被拆分成不同的键。

最好将密钥路径存储在数组中，如下所示：['db'，'mongodb'，'user']，并使用以下函数动态分配值。

function set(obj, path, value) {
  var schema = obj;
  var pList = path.slice();
  var len = pList.length;
  for (var i = 0; i < len - 1; i++) {
    var elem = pList[i];
    if (!schema[elem]) schema[elem] = {};
    schema = schema[elem];
  }
  schema[pList[len - 1]] = value;
}
    
let path = ['db','mongodb','user'];
set(obj, path, 'root');

为这个有趣的话题留下答案。创建为对象设置动态属性的函数可能很困难。

const entity = {
  haveDogs: true,
  dogs: ['Maya', 'Perla']
}
function isObject(obj) {
  return obj instanceof Object && obj.constructor === Object;
}
function setSchema(key, schema, value) {
  if (!isObject(value)) {
    schema[key] = value;
    return
  }
      
  if (!schema[key]) schema[key] = {}
  schema[key] = mutate(schema[key], value);
}
function mutate(obj, newObjData) {
    const keys = Object.keys(newObjData)
    
    for (const key of keys) {
      let schema = obj
      const list = key.split('.')
      const value = newObjData[key]
      const total = list.length - 1
      
      if (list.length === 1) {
        setSchema(key, schema, value)
        continue
      }
      
      for (let i = 0; i < total; i++) {
        const elem = list[i];
        if (!schema[elem]) schema[elem] = {}
        schema = schema[elem]
      }
      
      const subField = list[total]
      setSchema(subField, schema, value)
    }
    return obj
}
mutate(entity, {
  haveDogs: false,
  'pet1.pet2.pet3.pet4.pet5': 'pets',
  'bestFriends.list': ['Maya', 'Lucas'],
  friends: {
    'whitelist.permitted': ['Maya', 'Perla'], 
    'party.blocked': ['Juan', 'Trump']
  }
})
console.log('[entity]', entity)