在这里我提供了更多的方法，这些方法在很多方面看起来都更快:

选项1:Split string on。Or [Or] Or ' Or "，颠倒过来，跳过空项。

function getValue(path, origin) {
    if (origin === void 0 || origin === null) origin = self ? self : this;
    if (typeof path !== 'string') path = '' + path;
    var parts = path.split(/\[|\]|\.|'|"/g).reverse(), name; // (why reverse? because it's usually faster to pop off the end of an array)
    while (parts.length) { name=parts.pop(); if (name) origin=origin[name]; }
    return origin;
}

选项2(最快的，除了eval):低级字符扫描(没有regex/split/等等，只是一个快速字符扫描)。 注意:该命令不支持索引引用。

function getValue(path, origin) {
    if (origin === void 0 || origin === null) origin = self ? self : this;
    if (typeof path !== 'string') path = '' + path;
    var c = '', pc, i = 0, n = path.length, name = '';
    if (n) while (i<=n) ((c = path[i++]) == '.' || c == '[' || c == ']' || c == void 0) ? (name?(origin = origin[name], name = ''):(pc=='.'||pc=='['||pc==']'&&c==']'?i=n+2:void 0),pc=c) : name += c;
    if (i==n+2) throw "Invalid path: "+path;
    return origin;
} // (around 1,000,000+/- ops/sec)

选项3:(新:选项2扩展到支持引号-有点慢，但仍然很快)

function getValue(path, origin) {
    if (origin === void 0 || origin === null) origin = self ? self : this;
    if (typeof path !== 'string') path = '' + path;
    var c, pc, i = 0, n = path.length, name = '', q;
    while (i<=n)
        ((c = path[i++]) == '.' || c == '[' || c == ']' || c == "'" || c == '"' || c == void 0) ? (c==q&&path[i]==']'?q='':q?name+=c:name?(origin?origin=origin[name]:i=n+2,name='') : (pc=='['&&(c=='"'||c=="'")?q=c:pc=='.'||pc=='['||pc==']'&&c==']'||pc=='"'||pc=="'"?i=n+2:void 0), pc=c) : name += c;
    if (i==n+2 || name) throw "Invalid path: "+path;
    return origin;
}

JSPerf： http://jsperf.com/ways-to-dereference-a-delimited-property-string/3

"eval(...)" is still king though (performance wise that is). If you have property paths directly under your control, there shouldn't be any issues with using 'eval' (especially if speed is desired). If pulling property paths "over the wire" (on the line!? lol :P), then yes, use something else to be safe. Only an idiot would say to never use "eval" at all, as there ARE good reasons when to use it. Also, "It is used in Doug Crockford's JSON parser." If the input is safe, then no problems at all. Use the right tool for the right job, that's it.

这可能永远都不会曝光……但不管怎样，它在这里。

将[]括号语法替换为。 继续前进。字符 删除空白字符串 找到路径(否则未定义)

(为了找到一个对象的路径，使用这个pathTo解决方案。)

// "one liner" (ES6) const deep_value = (obj, path) => path .replace(/\[|\]\.?/g, '.') .split('.') .filter(s => s) .reduce((acc, val) => acc && acc[val], obj); // ... and that's it. var someObject = { 'part1' : { 'name': 'Part 1', 'size': '20', 'qty' : '50' }, 'part2' : { 'name': 'Part 2', 'size': '15', 'qty' : '60' }, 'part3' : [ { 'name': 'Part 3A', 'size': '10', 'qty' : '20' } // ... ], 'pa[rt3' : [ { 'name': 'Part 3A', 'size': '10', 'qty' : '20' } // ... ] }; console.log(deep_value(someObject, "part1.name")); // Part 1 console.log(deep_value(someObject, "part2.qty")); // 60 console.log(deep_value(someObject, "part3[0].name")); // Part 3A console.log(deep_value(someObject, "part3[0].....name")); // Part 3A - invalid blank paths removed console.log(deep_value(someObject, "pa[rt3[0].name")); // undefined - name does not support square brackets

我认为你的要求是:

var part1name = someObject.part1.name;
var part2quantity = someObject.part2.qty;
var part3name1 =  someObject.part3[0].name;

你可以这样问:

var part1name = someObject["part1"]["name"];
var part2quantity = someObject["part2"]["qty"];
var part3name1 =  someObject["part3"][0]["name"];

这两种方法都可行

也许这是你自找的

var partName = "part1";
var nameStr = "name";

var part1name = someObject[partName][nameStr];

终于轮到你自找麻烦了

var partName = "part1.name";

var partBits = partName.split(".");

var part1name = someObject[partBits[0]][partBits[1]];

如果你需要访问不同的嵌套键，而不知道它在编码时(这将是微不足道的)，你可以使用数组符号访问器:

var part1name = someObject['part1']['name'];
var part2quantity = someObject['part2']['qty'];
var part3name1 =  someObject['part3'][0]['name'];

它们等价于点符号访问器，并且可能在运行时发生变化，例如:

var part = 'part1';
var property = 'name';

var part1name = someObject[part][property];

等于

var part1name = someObject['part1']['name'];

or

var part1name = someObject.part1.name;

我希望这能解决你的问题…

EDIT

我不会使用字符串来维护某种xpath查询来访问对象值。 因为你必须调用一个函数来解析查询和检索值，我会遵循另一条路径(不是:

var part1name = function(){ return this.part1.name; }
var part2quantity = function() { return this['part2']['qty']; }
var part3name1 =  function() { return this.part3[0]['name'];}

// usage: part1name.apply(someObject);

或者，如果你不习惯apply方法

var part1name = function(obj){ return obj.part1.name; }
var part2quantity = function(obj) { return obj['part2']['qty']; }
var part3name1 =  function(obj) { return obj.part3[0]['name'];}

// usage: part1name(someObject);

函数更短，更清晰，解释器会为你检查语法错误等等。

顺便说一下，我觉得在适当的时候做一个简单的任务就足够了……

我已经看了所有其他的答案，决定在更可读的代码中添加改进:

function getObjectValByString(obj, str) {
if (typeof obj === "string") return obj;

const fields = str.split(".");

return getObjectValByString(obj[fields[0]], fields.slice(1).join("."));}

下面是一个代码片段:

let someObject = { 合作伙伴:{ id:“目标”, 人:{ 名称:“蚂蚁”, an:{名称:“ESM”}， }， }， }; 函数getObjectValByString(obj, str) { If (typeof obj === "string")返回obj; Const fields = str.split("."); 返回getObjectValByString(obj[fields[0]]， fields.slice(1).join(".")); ｝ const result = getObjectValByString(someObject， "partner.person.an.name"); console.log ({ 结果, })；

请注意，以下选项并不适用于所有有效的unicode属性名(但据我所知，其他选项也不适用)。

const PATTERN = /[\^|\[|\.]([$|\w]+)/gu function propValue(o, s) { const names = [] for(let [, name] of [...s.matchAll(PATTERN)]) names.push(name) return names.reduce((p, propName) => { if(!p.hasOwnProperty(propName)) throw 'invalid property name' return p[propName] }, o) } let path = 'myObject.1._property2[0][0].$property3' let o = { 1: { _property2: [ [{ $property3: 'Hello World' }] ] } } console.log(propValue(o, path)) // 'Hello World'