jQuery：如何使用“$”而不是“jQuery”？

Question

I have simple jQuery in my site, yet I keep getting this error:

Uncaught TypeError: Property '$' of object [object DOMWindow] is not a function

The error only appears if I use "$" instead of "jQuery".

// This works
jQuery(document).ready(function() {
    jQuery('#pass').keyup( ... );
});

// This doesn't
$(document).ready(function() {
    $('#pass').keyup( ... );
});

Do I need to do anything to use "$"?

Answer 1

You can wrap your code:

(function($) {
    // here $ would be point to jQuery object
    $(document).ready(function() {
        $('#pass').keyup( ... );
    });
})(jQuery);

Answer 2

You probably have jQuery noConflict mode enabled somewhere in your code, see: http://api.jquery.com/jQuery.noConflict/

jQuery.noConflict(); // Stops $ from workng

Answer 3

First, jQuery objects are a lot like arrays, so [object DOMWindow] actually is a jQuery object most likely.

You might have a syntax error, like a missing semicolon, right before the call to $(document) which is making the $ look like a property access.