“[变量]在定义之前使用”错误 [英] "[Variable] was used before it was defined" error

问题描述

我有几个这样的错误，我不知道如何正确解决它，问题是我有很多javascript文件（分离以便于维护）和我包含插件等等。

I have several of these errors and I am not sure how to "properly" solve it, the thing is that I have many javascript files (Seperated for easier maintainability) and I include plugins et cetera.

所以在这个例子中我使用来自 http：/的快捷方式/www.openjs.com/scripts/events/keyboard_shortcuts/

So in this example I use shortcut which is from http://www.openjs.com/scripts/events/keyboard_shortcuts/

这只是定义快捷方式

shortcut = {.......

然后当我在我的代码中使用它时

then when I in my code use it like

 shortcut.add("F1", function () { showDialog(); }, { 'type': 'keydown', 'propagate': false, 'target': editor_document });

jslint会抱怨

JS Lint：'快捷'在定义之前使用过。

JS Lint: 'shortcut' was used before it was defined.

我也有自己的代码在其他文件中声明的函数，那么解决这个问题的正确方法是什么？

I also have my own code where I use functions declared in other files, so what is the "right" way to solve this

推荐答案

如果变量是由另一个文件定义的，你可以告诉它JSLint通过以下格式提供评论：

If the variable is defined by another file, you can tell JSLint by providing a comment in the following format:

/*global shortcut*/

您可以通过逗号分隔它们来为多个变量执行此操作。附加：和 true 或 false （默认为 false ）将指定当前文件是否可以重新分配变量：

You can do this for a number of variables by comma separating them. Appending : and true or false (defaults to false) will specify whether the variable can be reassigned by the current file:

/*global shortcut:false, otherVar:true*/

---

您缺少 var 关键字，该关键字用于定义全局和函数范围的变量。

---

You're missing the var keyword, which is used to define a variable for the global and function scopes.

var shortcut = { }

您需要<对于定义的每个变量，使用 var ，否则会遇到大量问题。

You need to use var for every variable defined, else you'll run into a mass of problems.

可以通过省略 var 关键字来创建隐式全局变量，但它是高度皱眉，根本不推荐。如果需要从内部作用域创建全局变量，可以将对象添加到窗口，或者根据上下文， this ：

It is possible to create implicit globals by omitting the var keyword, but it's highly frowned upon and not at all recommended. If you need to create a global variable from an inner scope, you can add the object to window or, depending on the context, this:

function defineShortcut() {
    window.shortcut = {};
    /* or this.shortcut = {}; */
}

defineShortcut();

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