Javascript相当于通过引用分配？ [英] Javascript equivalent of assign by reference?

问题描述

有没有什么方法可以通过将局部变量指向对象属性来减少Javascript中的冗长？

Is there any way I can be less verbose in Javascript by pointing a local variable by to an objects property?

例如在PHP中我可以这样做：

For instance in PHP I can do this:

$obj->subobject->property = 'Foo';
$property =& $obj->subobject->property;
$property =  'Bar';
echo $obj->subobject->property;
// output 'Bar'

这不是一个很好的例子，但你明白了。

It's not a very good example but you get the idea.

我想在Javascript中复制此行为。我经常不得不深入到物体中，这让我很烦恼：

I want to copy this behaviour in Javascript. I'm quite often having to go quite deep into objects and it's getting quite annoying having to do:

if (please.stop.making.me[somevar].type.so.much.length) {
    please.stop.making.me[somevar].type.so.much[newSubObjectKey] = anObject;
}

// perform more operations on the object down here

阅读起来容易得多，输入也容易多了：

It would be a lot easier to read and a lot easier to type:

var subObj = is.much.easier.to.type.once;
if (subObj.length) {
     subObj[newSubObjectKey] = anObject;
}

// now that's much better

我知道我应该知道这一点，但我只是在Javascript中推进高级新手。

I know I should really know this already, but I'm just advancing to "advanced novice" in Javascript.

推荐答案

在Javascript中，一切是按值传递的，但变量的类型将决定它是否是通过值传递的引用;

In Javascript, everything is passed by value, but the variable's type will determine whether it's a reference passed by value or not;

• 对象是引用


• 原语（数字，字符串等）按值传递。

简单来说，如果将变量传递给一个数组的函数，在函数中修改它将影响父类。

In simple terms, if you pass a variable to a function that's an array, modifying it in the function will affect the parent.

但是，在数组中传递值不会。当然，绝对没有什么能阻止你在一个对象中包装一个原语，以确保它像一个指针一样工作。

However, passing it a value in the array will not. Naturally, there's absolutely nothing stopping you wrapping a primitive in an object to ensure it works like a "pointer".

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