使对象静态并仍然分配和更改它

Question

我想使用一个静态对象，将它赋值给一个新的变量并改变它。

var MY_STATIC: {message: "I am static"};
var test = MY_STATIC;

test.message = "I am not static enough";

console.log(MY_STATIC.messsage);  ==> I am not static enough

但我希望 MY_STATIC.message 仍然 "I am static" 以便稍后再次使用它。我怎样才能使对象保持不变，尽管我分配和更改它

Answer 1

您可能想使用 Object.create() 来创建 MY_STATIC 对象的新实例：

var MY_STATIC = {message: "I am static"};
var test = Object.create(MY_STATIC);
test.message = "I am not static enough";

console.log(test.message);
console.log(MY_STATIC.message);

Answer 2

在兼容 ES5 的引擎上，您可以 "freeze" an object:

var static = Object.freeze({message: "I am static"});
snippet.log(static.message); // "I am static"
static.message = "Not!";
snippet.log(static.message); // "I am static"

<!-- Script provides the `snippet` object, see http://meta.stackexchange.com/a/242144/134069 -->
<script src="http://tjcrowder.github.io/simple-snippets-console/snippet.js"></script>

Answer 3

通过设置 obj1=obj2，您将通过 ref 传递它们。您在这里需要的是按值传递它们，因此请使用此代码

 var MY_STATIC = {message:"Static I am"};

 function Clone(x) {
    for(prop in x)
    this[prop] = (typeof(x[prop]) == 'object')? 
                  new Clone(x[prop]) : x[prop];
 }

 (function(x){
     var test  = new Clone(x);
     test.message = 'Not static';
 })(MY_STATIC)

使对象静态并仍然分配和更改它

Make object static and still assign and change it

javascript

object