代码:

// extends 'from' object with members from 'to'. If 'to' is null, a deep clone of 'from' is returned
function extend(from, to)
{
    if (from == null || typeof from != "object") return from;
    if (from.constructor != Object && from.constructor != Array) return from;
    if (from.constructor == Date || from.constructor == RegExp || from.constructor == Function ||
        from.constructor == String || from.constructor == Number || from.constructor == Boolean)
        return new from.constructor(from);

    to = to || new from.constructor();

    for (var name in from)
    {
        to[name] = typeof to[name] == "undefined" ? extend(from[name], null) : to[name];
    }

    return to;
}

测试:

var obj =
{
    date: new Date(),
    func: function(q) { return 1 + q; },
    num: 123,
    text: "asdasd",
    array: [1, "asd"],
    regex: new RegExp(/aaa/i),
    subobj:
    {
        num: 234,
        text: "asdsaD"
    }
}

var clone = extend(obj);

对于未来的参考,目前的 ECMAScript 6 草案将 Object.assign 引入为克隆对象的一种方式。

var obj1 = { a: true, b: 1 };
var obj2 = Object.assign(obj1);
console.log(obj2); // { a: true, b: 1 }

在编写时,支持仅限于Firefox 34在浏览器中,所以它还不能在生产代码中使用(除非您正在编写Firefox扩展)。

这是我正在使用的:

function cloneObject(obj) {
    var clone = {};
    for(var i in obj) {
        if(typeof(obj[i])=="object" && obj[i] != null)
            clone[i] = cloneObject(obj[i]);
        else
            clone[i] = obj[i];
    }
    return clone;
}

如下图所示,John Resig的jQuery克隆器将非数字属性的<unk>转化为非数字属性的对象,而RegDwight的JSON克隆器将非数字属性放下。

function jQueryClone(obj) {
   return jQuery.extend(true, {}, obj)
}

function JSONClone(obj) {
   return JSON.parse(JSON.stringify(obj))
}

var arrayLikeObj = [[1, "a", "b"], [2, "b", "a"]];
arrayLikeObj.names = ["m", "n", "o"];
var JSONCopy = JSONClone(arrayLikeObj);
var jQueryCopy = jQueryClone(arrayLikeObj);

alert("Is arrayLikeObj an array instance?" + (arrayLikeObj instanceof Array) +
      "\nIs the jQueryClone an array instance? " + (jQueryCopy instanceof Array) +
      "\nWhat are the arrayLikeObj names? " + arrayLikeObj.names +
      "\nAnd what are the JSONClone names? " + JSONCopy.names)

下面是同一个对象的两个例子,我发现了它,目前正在使用它,它很简单,易于使用。

var objToCreate = JSON.parse(JSON.stringify(cloneThis));

通过提出新的方法 Object.fromEntries(),它支持一些浏览器的更新的版本(参考)。

const obj = { key1: {key11: “key11”, key12: “key12”, key13: {key131: 22}}, key2: {key21: “key21”, key22: “key22”}, key3: “key3”, key4: [1,2,3, {key: “value”} } const cloneObj = (obj) => { if (Object(obj)!== obj) return obj; other if (Array.isArray(obj)) return obj.map(cloneObj); return Object.fromEntries(Object.entries(obj).map(([k,v])