在javascript中深度复制嵌套对象的数组
这个问题在这里已经有了答案:
你有两个主要选择:
使用JSON.stringify
和JSON.parse
:
var copy = JSON.parse(JSON.stringify(original));
但我从来不喜欢那样。 往返文本效率低下,除非您编写替代者和reviver,否则它不会正确处理Date
, RegExp
, undefined
等值。
使用递归函数,如下所示:
var toString = Object.prototype.toString;
function deepCopy(obj) {
var rv;
switch (typeof obj) {
case "object":
if (obj === null) {
// null => null
rv = null;
} else {
switch (toString.call(obj)) {
case "[object Array]":
// It's an array, create a new array with
// deep copies of the entries
rv = obj.map(deepCopy);
break;
case "[object Date]":
// Clone the date
rv = new Date(obj);
break;
case "[object RegExp]":
// Clone the RegExp
rv = new RegExp(obj);
break;
// ...probably a few others
default:
// Some other kind of object, deep-copy its
// properties into a new object
rv = Object.keys(obj).reduce(function(prev, key) {
prev[key] = deepCopy(obj[key]);
return prev;
}, {});
break;
}
}
break;
default:
// It's a primitive, copy via assignment
rv = obj;
break;
}
return rv;
}
var a = [1, {foo: "bar"}, ['a', 'b'], new Date()];
snippet.log(JSON.stringify(a));
var b = deepCopy(a);
snippet.log(JSON.stringify(b));
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