我从Ricardo Tomasi的回答中复制了以下内容，并进行了修改，以创建还不存在的子对象。它的效率有点低(更多的if和创建空对象)，但应该很好。

它还允许我们做Object。Prop (obj， 'a.b'， false)我们之前做不到。不幸的是，它仍然不允许我们赋值为undefined…我还不知道该怎么做。

/**
 * Object.prop()
 *
 * Allows dot-notation access to object properties for both getting and setting.
 *
 * @param {Object} obj    The object we're getting from or setting
 * @param {string} prop   The dot-notated string defining the property location
 * @param {mixed}  val    For setting only; the value to set
 */
 Object.prop = function(obj, prop, val){
   var props = prop.split('.'),
       final = props.pop(),
       p;

   for (var i = 0; i < props.length; i++) {
     p = props[i];
     if (typeof obj[p] === 'undefined') {
       // If we're setting
       if (typeof val !== 'undefined') {
         // If we're not at the end of the props, keep adding new empty objects
         if (i != props.length)
           obj[p] = {};
       }
       else
         return undefined;
     }
     obj = obj[p]
   }
   return typeof val !== "undefined" ? (obj[final] = val) : obj[final]
 }

2021

您不需要每次希望在程序中添加新功能时都拉入另一个依赖项。现代JS是非常能干的和可选的链接操作符?。现在得到了广泛的支持，使这类任务变得非常简单。

只需一行代码，我们就可以编写get，它接受一个输入对象t和字符串路径。它适用于任何嵌套级别的对象和数组

Const get = (t, path) => path.split(“。”)。Reduce ((r, k) => r?。[k], t) Const mydata = {: {b: [0, {c: {d:[“你好”、“世界 " ] } } ] } } console.log (get (mydata,“a.b.1.c.d.0”)) console.log (get (mydata,“a.b.1.c.d.1”)) console.log (get (mydata,“a.b.x.y.z”))

"hello"
"world"
undefined

从最初的帖子到现在已经很多年了。 现在有一个很棒的库叫做object-path。 https://github.com/mariocasciaro/object-path

可在NPM和BOWER上使用 https://www.npmjs.com/package/object-path

很简单:

objectPath.get(obj, "a.c.1");  //returns "f"
objectPath.set(obj, "a.j.0.f", "m");

并且适用于深度嵌套的属性和数组。

如果您希望将任何包含点符号键的对象转换为这些键的数组版本，可以使用此方法。

这将转换为

{
  name: 'Andy',
  brothers.0: 'Bob'
  brothers.1: 'Steve'
  brothers.2: 'Jack'
  sisters.0: 'Sally'
}

to

{
  name: 'Andy',
  brothers: ['Bob', 'Steve', 'Jack']
  sisters: ['Sally']
}

convertDotNotationToArray(objectWithDotNotation) {

    Object.entries(objectWithDotNotation).forEach(([key, val]) => {

      // Is the key of dot notation 
      if (key.includes('.')) {
        const [name, index] = key.split('.');

        // If you have not created an array version, create one 
        if (!objectWithDotNotation[name]) {
          objectWithDotNotation[name] = new Array();
        }

        // Save the value in the newly created array at the specific index 
        objectWithDotNotation[name][index] = val;
        // Delete the current dot notation key val
        delete objectWithDotNotation[key];
      }
    });

}

这是ninjagecko提出的我的扩展方案。

对我来说，简单的字符串表示法是不够的，所以下面的版本支持如下内容:

index(obj, 'data.accounts[0].address[0].postcode');

/**
 * Get object by index
 * @supported
 * - arrays supported
 * - array indexes supported
 * @not-supported
 * - multiple arrays
 * @issues:
 *  index(myAccount, 'accounts[0].address[0].id') - works fine
 *  index(myAccount, 'accounts[].address[0].id') - doesnt work
 * @Example:
 * index(obj, 'data.accounts[].id') => returns array of id's
 * index(obj, 'data.accounts[0].id') => returns id of 0 element from array
 * index(obj, 'data.accounts[0].addresses.list[0].id') => error
 * @param obj
 * @param path
 * @returns {any}
 */
var index = function(obj, path, isArray?, arrIndex?){

    // is an array
    if(typeof isArray === 'undefined') isArray = false;
    // array index,
    // if null, will take all indexes
    if(typeof arrIndex === 'undefined') arrIndex = null;

    var _arrIndex = null;

    var reduceArrayTag = function(i, subArrIndex){
        return i.replace(/(\[)([\d]{0,})(\])/, (i) => {
            var tmp = i.match(/(\[)([\d]{0,})(\])/);
            isArray = true;
            if(subArrIndex){
                _arrIndex =  (tmp[2] !== '') ? tmp[2] : null;
            }else{
                arrIndex =  (tmp[2] !== '') ? tmp[2] : null;
            }
            return '';
        });
    }

    function byIndex(obj, i) {
        // if is an array
        if(isArray){
            isArray = false;
            i = reduceArrayTag(i, true);
            // if array index is null,
            // return an array of with values from every index
            if(!arrIndex){
                var arrValues = [];
                _.forEach(obj, (el) => {
                    arrValues.push(index(el, i, isArray, arrIndex));
                })
                return arrValues;
            }
            // if array index is specified
            var value = obj[arrIndex][i];
            if(isArray){
                arrIndex = _arrIndex;
            }else{
                arrIndex = null;
            }
            return value;
        }else{
            // remove [] from notation,
            // if [] has been removed, check the index of array
            i = reduceArrayTag(i, false);
            return obj[i]
        }
    }

    // reduce with the byIndex method
    return path.split('.').reduce(byIndex, obj)
}

我建议分割路径，迭代它，减少你拥有的对象。此建议使用对于缺失属性的默认值。

const getValue = (object, keys) => keys.split('.')。Reduce ((o, k) => (o || {})[k]，对象); console.log (getValue({答:{' 1 ',c:‘2’}},' a.b ')); console.log (getValue({答:{' 1 ',c:‘2’}},' foo.bar.baz '));