JSLint: was used before it was defined

javascript undefined jslint
Chun ping Wang picture Chun ping Wang · Mar 8, 2012 · Viewed 70.1k times · Source

Hi I have the 3 javascript files.

  • jquery.js
  • utility.js
  • file1.js

In file1.js I have 

jQuery.noConflict()
jQuery(document).ready(function($) { 
 // ....
});

I get an error 'jQuery' was used before it was defined. and 'document' was used before it was defined.

How do I safely get rid of this warning.

If I do 

var document = document || {};

then in my utility.js if it is used, it would be null in IE and ok in firefox.

What is the best solution to this?

Answer

Quentin picture Quentin · Mar 8, 2012

From the documentation

JSLint also recognizes a /*global */ directive that can indicate to JSLint that variables used in this file were defined in other files. The comment can contain a comma separated list of names. Each name can optionally be followed by a colon and either true or false, true indicating that the variable may be assigned to by this file, and false indicating that assignment is not allowed (which is the default). The directive respects function scope.

Some globals can be predefined for you. Select the Assume a browser (browser) option to predefine the standard global properties that are supplied by web browsers, such as document and addEventListener.

Example:

/*jslint browser: true*/
/*global $, jQuery*/

Related questions

How can I determine if a variable is 'undefined' or 'null'?

How do I determine if variable is undefined or null? My code is as follows: var EmpName = $("div#esd-names div#name").attr('class'); if(EmpName == 'undefined'){ // DO SOMETHING }; <div id="esd-names"> <div id="name"></div&…

Read More
How can I check for "undefined" in JavaScript?

What is the most appropriate way to test if a variable is undefined in JavaScript? I've seen several possible ways: if (window.myVariable) Or if (typeof(myVariable) != "undefined") Or if (myVariable) // This throws an error if undefined. Should this be …

Read More
Is there a standard function to check for null, undefined, or blank variables in JavaScript?

Is there a universal JavaScript function that checks that a variable has a value and ensures that it's not undefined or null? I've got this code, but I'm not sure if it covers all cases: function isEmpty(val){ return (val === …

Read More