Calling function from within jquery plugin

I'm writing my first jquery plugin and wondered what the correct/best practice way of referencing another function from within a plugin was? Is there a better way to define bar in my plugin scri开发者_StackOverflow中文版pt. Should it be within function($) ? I'd also like it to be available to other plugins within the script.

function bar() {
    return 'is this best paractice?';
}

(function($) {
    $.fn.foo = function() { 
        alert(bar());
    };
}(jQuery));

Why doesn't something like this work:

(function($) {
    $.fn.bar = function() {
        return 'is this best paractice?';
    };
}(jQuery));

(function($) {
    $.fn.foo = function() { 
        alert(bar());
    };
}(jQuery));

Thanks

Functions added to $.fn will be used as jQuery plugins. If you just want to provide a global function from your plugin you add it to $ directly (e.g. $.bar = function() ...).

If you just want use the function internally for your plugin put it within function($). That way you make it available only in that scope (the anonymous function) and not everywhere.