如何将对象的关键与其价值相结合?

function deepClone(o) {
    var keys = Object.keys(o);
    var values = Object.values(o);

    var clone = {};

    keys.forEach(function(key, i) {
        clone[key] = typeof values[i] == 'object' ? Object.create(values[i]) : values[i];
    });

    return clone;
}

注意: 这种方法不一定会做更深的复制,但它只会用一个内部对象的深度复制,这意味着当你给出像 {a: {b: {c: null}}} 这样的东西时,它只会克隆直接在它们内部的对象,所以 deepClone(a.b.c)技术上是对 a.b.c 的参考,而 deepClone(a.b)则是克隆,而不是参考。

因为回归只是太昂贵的JavaScript,我发现的大多数答案是使用回归,而JSON方法将错过非JSON转换部分(功能等)。所以我做了一些研究,并发现这个拖拉机技术避免它。

/*
 * Trampoline to avoid recursion in JavaScript, see:
 *     https://www.integralist.co.uk/posts/functional-recursive-javascript-programming/
 */
function trampoline() {
    var func = arguments[0];
    var args = [];
    for (var i = 1; i < arguments.length; i++) {
        args[i - 1] = arguments[i];
    }

    var currentBatch = func.apply(this, args);
    var nextBatch = [];

    while (currentBatch && currentBatch.length > 0) {
        currentBatch.forEach(function(eachFunc) {
            var ret = eachFunc();
            if (ret && ret.length > 0) {
                nextBatch = nextBatch.concat(ret);
            }
        });

        currentBatch = nextBatch;
        nextBatch = [];
    }
};

/*
 *  Deep clone an object using the trampoline technique.
 *
 *  @param target {Object} Object to clone
 *  @return {Object} Cloned object.
 */
function clone(target) {
    if (typeof target !== 'object') {
        return target;
    }
    if (target == null || Object.keys(target).length == 0) {
        return target;
    }

    function _clone(b, a) {
        var nextBatch = [];
        for (var key in b) {
            if (typeof b[key] === 'object' && b[key] !== null) {
                if (b[key] instanceof Array) {
                    a[key] = [];
                }
                else {
                    a[key] = {};
                }
                nextBatch.push(_clone.bind(null, b[key], a[key]));
            }
            else {
                a[key] = b[key];
            }
        }
        return nextBatch;
    };

    var ret = target instanceof Array ? [] : {};
    (trampoline.bind(null, _clone))(target, ret);
    return ret;
};

我的场景略有不同,我有一個物體,擁有<unk>的物體以及功能,因此,Object.assign() 和 JSON.stringify() 並沒有解決我的問題。

因此,我决定做一个简单的功能,使用内置的方法来复制一个对象,其字面特性,其粘着的对象和功能。

let deepCopy = (target, source) => {
    Object.assign(target, source);
    // check if there's any nested objects
    Object.keys(source).forEach((prop) => {
        /**
          * assign function copies functions and
          * literals (int, strings, etc...)
          * except for objects and arrays, so:
          */
        if (typeof(source[prop]) === 'object') {
            // check if the item is, in fact, an array
            if (Array.isArray(source[prop])) {
                // clear the copied referenece of nested array
                target[prop] = Array();
                // iterate array's item and copy over
                source[prop].forEach((item, index) => {
                    // array's items could be objects too!
                    if (typeof(item) === 'object') {
                        // clear the copied referenece of nested objects
                        target[prop][index] = Object();
                        // and re do the process for nested objects
                        deepCopy(target[prop][index], item);
                    } else {
                        target[prop].push(item);
                    }
                });
            // otherwise, treat it as an object
            } else {
                // clear the copied referenece of nested objects
                target[prop] = Object();
                // and re do the process for nested objects
                deepCopy(target[prop], source[prop]);
            }
        }
    });
};

下面是测试代码:

let a = {
    name: 'Human', 
    func: () => {
        console.log('Hi!');
    }, 
    prop: {
        age: 21, 
        info: {
            hasShirt: true, 
            hasHat: false
        }
    },
    mark: [89, 92, { exam: [1, 2, 3] }]
};

let b = Object();

deepCopy(b, a);

a.name = 'Alien';
a.func = () => { console.log('Wassup!'); };
a.prop.age = 1024;
a.prop.info.hasShirt = false;
a.mark[0] = 87;
a.mark[1] = 91;
a.mark[2].exam = [4, 5, 6];

console.log(a); // updated props
console.log(b);

对于效率相关的担忧,我认为这是我遇到的问题的最简单和最有效的解决方案,我会欣赏任何关于这个算法的评论,这可能会使它更有效。

2017年例子:

let objectToCopy = someObj;
let copyOfObject = {};
Object.defineProperties(copyOfObject, Object.getOwnPropertyDescriptors(objectToCopy));
// copyOfObject will now be the same as objectToCopy

这是我的解决方案,没有使用任何图书馆或本地JavaScript功能。

function deepClone(obj) {
  if (typeof obj !== "object") {
    return obj;
  } else {
    let newObj =
      typeof obj === "object" && obj.length !== undefined ? [] : {};
    for (let key in obj) {
      if (key) {
        newObj[key] = deepClone(obj[key]);
      }
    }
    return newObj;
  }
}

没有触摸原型遗产,你可以如下深孤独的物体和岩石;

函数 objectClone(o){ var ot = Array.isArray(o); return o!== null && typeof o === “object”? Object.keys(o).reduce((r,k) => o[k]!== null && typeof o[k] === “object”? (r[k] = objectClone(o[k]),r) : (r[k] = o[k],r), ot?