問題描述

我正在為 jQuery 開發一個插件，我收到了這個 JSLint 錯誤:

I'm working on a plug-in for jQuery and I'm getting this JSLint error:

Problem at line 80 character 45: Do not use 'new' for side effects.

(new jQuery.fasterTrim(this, options));

我沒有太多運氣找到有關此 JSLint 錯誤或 new 可能具有的任何副作用的信息.

I haven't had much luck finding info on this JSLint error or on any side effects that new might have.

我試過 谷歌搜索不要使用'新'來獲得副作用."并得到 0 個結果.必應給了我 2 個結果，但它們都只是引用了 JSLint 源.希望這個問題會改變這一點.:-)

I've tried Googling for "Do not use 'new' for side effects." and got 0 results. Binging gives me 2 results but they both just reference the JSLint source. Hopefully this question will change that. :-)

更新 #1:以下是上下文的更多來源:

Update #1: Here's more source for the context:

  jQuery.fn.fasterTrim = function(options) {
    return this.each(function() {
      (new jQuery.fasterTrim(this, options));
    });
  };

更新 #2:我使用 Starter jQuery 插件生成器 作為我的插件的模板，其中包含該代碼.

Update #2: I used the Starter jQuery plug-in generator as a template for my plug-in, which has that code in it.

推薦答案

Travis，我是 Starter 網站的開發者.

Travis, I am the developer behind the Starter site.

@Pointy 一針見血.以這種方式編寫 Starter 代碼的原因是因為我們確實需要一個新對象，我們只是不需要在那時存儲對它的引用.

@Pointy hit the nail on the head. The reason the Starter code is written that way is because we do need a new object, we just don't need to store a reference to it at that point.

只需從

(new jQuery.fasterTrim(this, options)); 

到

var fT = new jQuery.fasterTrim(this, options);

會像你發現的那樣安撫 JSLint.

will appease JSLint as you have found.

Starter 插件設置遵循 jQuery UI 模式，即在元素的 data 集中存儲對對象的引用.這就是正在發生的事情:

The Starter plugin setup follows the jQuery UI pattern of storing a reference to the object in the data set for the element. So this is what is happening:

1. 創建新對象(通過 new)
2. 使用 jQuery 的 data 將實例附加到 DOM 元素:$(el).data('FasterTrim', this)

1. New object is created (via new)
2. The instance is attached to the DOM element using jQuery's data :$(el).data('FasterTrim', this)

返回的對象沒有用處，因此沒有var聲明.我將考慮更改聲明并清理輸出以使 JSLint 開箱即用.

There is no use for the object that is returned, and thus no var declaration made. I will look into changing the declaration and cleaning up the output to pass JSLint out of the box.

更多背景知識:

使用 data 存儲對象的好處是我們可以在以后隨時通過調用訪問該對象:$("#your_selector").data('FasterTrim').但是，如果您的插件不需要以這種方式在中間流中訪問(意思是，它在一次調用中設置并且不提供未來交互)，則不需要存儲引用.