关于Javascript指向对象属性的指针的问题

发布于 2024-11-01 18:08:16 字数 743 浏览 1 评论 0原文

我想设置一个变量来指向新创建的对象中的属性以保存“查找”，如下例所示。基本上，我认为变量是对对象属性的引用。事实并非如此；看起来变量保存了值。第一个console.log是1（这是我想分配给photoGalleryMod.slide的值），但是当查看photoGalleryMod.slide时，它仍然是0。

有没有办法做到这一点？谢谢。

(function() {
    var instance;

    PhotoGalleryModule = function PhotoGalleryModule() {

        if (instance) {
            return instance;
        }

        instance = this;

        /* Properties */
        this.slide = 0;
    };
}());

window.photoGalleryMod = new PhotoGalleryModule();

/* Tried to set a variable so I could use test, instead of writing photoGalleryMod.slide all the time plus it saves a lookup */

var test = photoGalleryMod.slide;

test = test + 1;

console.log(test);
console.log(photoGalleryMod.slide);

原文

I wanted to set a variable to point to property in an newly created object to save a "lookup" as shown in the example below. Basically, I thought the variable is a reference to the object's property. This is not the case; it looks like the variable holds the value. The first console.log is 1 (which is the value I want to assign to photoGalleryMod.slide) but when looking at photoGalleryMod.slide, it's still 0.

Is there a way to do this? Thanks.

(function() {
    var instance;

    PhotoGalleryModule = function PhotoGalleryModule() {

        if (instance) {
            return instance;
        }

        instance = this;

        /* Properties */
        this.slide = 0;
    };
}());

window.photoGalleryMod = new PhotoGalleryModule();

/* Tried to set a variable so I could use test, instead of writing photoGalleryMod.slide all the time plus it saves a lookup */

var test = photoGalleryMod.slide;

test = test + 1;

console.log(test);
console.log(photoGalleryMod.slide);

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

爱*していゐ 2024-11-08 18:08:16

是的，您正在复制该值，因为“幻灯片”被设置为原始类型。试试这个：

this.slide = [0];

然后

var test = photoGalleryMod.slide;
test[0] = test[0] + 1;

更改日志记录：

console.log(test[0]);
console.log(photoGalleryMod.slide[0]);

在这种情况下，您将看到您确实拥有对同一对象的引用。与其他一些语言 (C++) 不同，JavaScript 中无法说“请给我这个变量的别名”。

Yes, you're making a copy of the value, because "slide" is set to a primitive type. Try this:

this.slide = [0];

and then

var test = photoGalleryMod.slide;
test[0] = test[0] + 1;

then change the logging:

console.log(test[0]);
console.log(photoGalleryMod.slide[0]);

In that case you'll see that you do have a reference to the same object. Unlike some other languages (C++) there's no way to say, "Please give me an alias for this variable" in JavaScript.

回复收藏 0 原文