如何在JavaScript中通过引用传递变量？
我有三个变量，我想对它们执行几个操作，所以我想把它们放在for循环中，并对每个变量执行操作.
伪代码:
myArray = new Array(var1, var2, var3);
for (var x = 0; x < myArray.length; x++){
// Do stuff to the array
makePretty(myArray[x]);
}
// Now do stuff to the updated variables
最好的方法是什么？
JavaScript中没有可用的"通过引用传递".可以传递对象(也就是说，可以通过值传递对对象的引用)，然后让函数修改对象内容:
function alterObject(obj) {
obj.foo = "goodbye";
}
var myObj = { foo: "hello world" };
alterObject(myObj);
alert(myObj.foo); // "goodbye" instead of "hello world"
如果需要，可以使用数字索引迭代数组的属性并修改数组的每个单元格.
var arr = [1, 2, 3];
for (var i = 0; i < arr.length; i++) {
arr[i] = arr[i] + 1;
}
需要注意的是，"通过引用传递"是一个非常具体的术语.这不仅仅意味着可以将引用传递给可修改的对象.相反，这意味着可以以允许函数在calling上下文中修改该值的方式传递简单变量.所以:
function swap(a, b) {
var tmp = a;
a = b;
b = tmp; //assign tmp to b
}
var x = 1, y = 2;
swap(x, y);
alert("x is " + x + ", y is " + y); // "x is 1, y is 2"
在像C++这样语言中，这样做是可能的，因为语言does(排序)具有按引用传递.
edit — this recently (March 2015) blew up on Reddit again over a blog post similar to mine mentioned below, though in this case about Java. It occurred to me while reading the back-and-forth in the Reddit comments that a big part of the confusion stems from the unfortunate collision involving the word "reference". The terminology "pass by reference" and "pass by value" predates the concept of having "objects" to work with in programming languages. It's really not about objects at all; it's about function parameters, and specifically how function parameters are "connected" (or not) to the calling environment. In particular, note that in a true pass-by-reference language — one that does involve objects — one would still have the ability to modify object contents, and it would look pretty much exactly like it does in JavaScript. However, one would also be able to modify the object reference in the calling environment, and that's the key thing that you can't do in JavaScript. A pass-by-reference language would pass not the reference itself, but a reference to the reference.
edit — here is a blog post on the topic. (Note the comment to that post that explains that C++ doesn't really have pass-by-reference. That is true. What C++ does have, however, is the ability to create references to plain variables, either explicitly at the point of function invocation to create a pointer, or implicitly when calling functions whose argument type signature calls for that to be done. Those are the key things JavaScript doesn't support.)