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

问题描述

我有几个这样的错误，我不确定如何正确地"解决它，问题是我有很多javascript文件(为了便于维护而分开使用)，并且包括了插件等等.

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.

因此，在此示例中，我使用来自 http://www.openjs.com的快捷方式/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

shortcut = {.......

然后，当我在代码中使用它时，

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:快捷方式"在定义之前就已使用.

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

我也有自己的代码，使用其他文件中声明的函数，那么解决此问题的正确"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，则可以通过提供以下格式的注释来告诉JSLint:

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

/*global shortcut*/

您可以通过用逗号分隔多个变量来执行此操作.追加:和 true 或 false (默认为 false )将指定变量是否可以由当前变量重新分配.文件:

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，该关键字用于为全局和函数作用域定义变量.

---

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

var shortcut = { }

您需要对定义的每个变量使用 var ，否则会遇到很多问题.

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

通过省略 var 关键字，可以 创建隐式全局变量，但对此却一无所知，根本不建议这样做.如果需要从内部范围创建全局变量，则可以将对象添加到 window 或根据上下文，将其添加到 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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