用jQuery和JavaScript深度复制JSON对象的方法
你有时可能需要复制一个JSON对象，jQuery提供了的extend方法以前是无法进行深度复制的，不过现在也已经支持了：
// Shallow copy var newObject = jQuery.extend({}, oldObject); // Deep copy var newObject = jQuery.extend(true, {}, oldObject);StackOverFlow的一位网友提供了一个深度复制的函数
Array.prototype.clone = function(doDeepCopy) {
if(doDeepCopy) {
var encountered = [{
a : this,
b : []
}];
var item,
levels = [{a:this, b:encountered[0].b, i:0}],
level = 0,
i = 0,
len = this.length;
while(i < len) {
item = levels[level].a[i];
if(Object.prototype.toString.call(item) === "[object Array]") {
for(var j = encountered.length - 1; j >= 0; j--) {
if(encountered[j].a === item) {
levels[level].b.push(encountered[j].b);
break;
}
}
if(j < 0) {
encountered.push(j = {
a : item,
b : []
});
levels[level].b.push(j.b);
levels[level].i = i + 1;
levels[++level] = {a:item, b:j.b, i:0};
i = -1;
len = item.length;
}
}
else {
levels[level].b.push(item);
}
if(++i == len && level > 0) {
levels.pop();
i = levels[--level].i;
len = levels[level].a.length;
}
}
return encountered[0].b;
}
else {
return this.slice(0);
}
};
不过此函数是加到Array对象原型上的，这意味着你使用 for in 枚举array数组时也会枚举出这个方法。这里有一个函数版本：
function clone(item) {
if (!item) { return item; } // null, undefined values check
var types = [ Number, String, Boolean ],
result;
// normalizing primitives if someone did new String('aaa'), or new Number('444');
types.forEach(function(type) {
if (item instanceof type) {
result = type( item );
}
});
if (typeof result == "undefined") {
if (Object.prototype.toString.call( item ) === "[object Array]") {
result = [];
item.forEach(function(child, index, array) {
result[index] = clone( child );
});
} else if (typeof item == "object") {
// testing that this is DOM
if (item.nodeType && typeof item.cloneNode == "function") {
var result = item.cloneNode( true );
} else if (!item.prototype) { // check that this is a literal
if (item instanceof Date) {
result = new Date(item);
} else {
// it is an object literal
result = {};
for (var i in item) {
result[i] = clone( item[i] );
}
}
} else {
// depending what you would like here,
// just keep the reference, or create new object
if (false && item.constructor) {
// would not advice to do that, reason? Read below
result = new item.constructor();
} else {
result = item;
}
}
} else {
result = item;
}
}
return result;
}
var copy = clone({
one : {
'one-one' : new String("hello"),
'one-two' : [
"one", "two", true, "four"
]
},
two : document.createElement("div"),
three : [
{
name : "three-one",
number : new Number("100"),
obj : new function() {
this.name = "Object test";
}
}
]
})
其实深度复制JavaScript对象还有一个更加简单的方法， 一行代码即可，比如：
var cloned = JSON.parse(JSON.stringify(objectToClone));
参考： http://stackoverflow.com/questions/122102/what-is-the-most-efficient-way-to-clone-an-object
正文到此结束
热门推荐
相关文章
Loading...
![[HBLOG]公众号](http://www.liuhaihua.cn/img/qrcode_gzh.jpg)
