[javascript] Is this how you define a function in jQuery?

Is this how you define a function in jQuery?

$(document).ready( function () {
    var MyBlah = function($blah) { alert($blah);  };
 });

Now to call the function I do:

MyBlah('hello');

jQuery.fn.extend({
    zigzag: function () {
        var text = $(this).text();
        var zigzagText = '';
        var toggle = true; //lower/uppper toggle
            $.each(text, function(i, nome) {
                zigzagText += (toggle) ? nome.toUpperCase() : nome.toLowerCase();
                toggle = (toggle) ? false : true;
            });
    return zigzagText;
    }
});

You can extend jQuery prototype and use your function as a jQuery method.

(function($)
{
    $.fn.MyBlah = function(blah)
    {
        $(this).addClass(blah);
        console.log('blah class added');
    };
})(jQuery);

jQuery(document).ready(function($)
{
    $('#blahElementId').MyBlah('newClass');
});

More info on extending jQuery prototype here: http://api.jquery.com/jquery.fn.extend/

No.

You define the functions exactly the same way you would in regular javascript.

//document ready
$(function(){
    myBlah();
})

var myBlah = function(blah){
    alert(blah);
}

Also: There is no need for the $

No, you can just write the function as:

$(document).ready(function() {
    MyBlah("hello");
});

function MyBlah(blah) {
    alert(blah);
}

This calls the function MyBlah on content ready.

That is how you define an anonymous function that gets called when the document is ready.

The following example show you how to define a function in jQuery. You will see a button “Click here”, when you click on it, we call our function “myFunction()”.

  $(document).ready(function(){
    $.myFunction = function(){ 
      alert('You have successfully defined the function!'); 
    }
    $(".btn").click(function(){
      $.myFunction();
    });
  });

You can see an example here: How to define a function in jQuery?