CODEWITHSUNDEEP
jquery
AnonyMouse
AnonyMouse

Reputation: 18630

How to pass a select to a jquery function

I have some javascript where I append an option to a select:

var myuniqueddl = $('#myuniqueddl');

$("<option value='0'>--- Select a value ---</option>").appendTo(myuniqueddl);

I'm actually trying to do this for another select as well.

I'm wondering to avoid code duplication should I be passing the ddl to a method to do this?

function(someType ddl)
{
   $("<option value='0'>--- Select a value ---</option>").appendTo(ddl);
}

Is this a bad idea to be passing a select to a method?

Any better way of doing this?

If this way is ok what type do I pass it in as?

Upvotes: 0

Views: 707

Answers (4)

user229044
user229044

Reputation: 239230

Firstly, yes, it's completely valid to pass a select element into a function to reduce code duplication. In this case, it seems like you're worried about having to type the same function call (appendTo) twice, which really isn't duplication.

Secondly, you cannot specify any type for a JavaScript function parameter. Variables in JavaScript are dynamically typed. You simply specify the variable name:

function myFunction(ddl) {
  $("<option value='0'>--- Select a value ---</option>").appendTo(ddl);
}

Upvotes: 5

Chris Baker
Chris Baker

Reputation: 50592

Javascript functions do not use type hinting, so your function signature:

function(someType ddl)

.. is not valid.

Further, I suggest making your function a little more flexible, and to eliminate the creating of DOM elements by passing strings to jQuery (not efficient, see this benchmark):

var addOption = function(sel, text, value) {
    if (typeof value == 'undefined')
        value = text;
   sel.options[sel.options.length] = new Option(text, value);
}
// usage: addOption($('#myuniqueddl'), '--- Select a value ---');
//    or: addOption($('#myuniqueddl'), '--- Select a value ---', 0);

Documentation

Upvotes: 3

Kyle Trauberman
Kyle Trauberman

Reputation: 25684

There is nothing wrong with this, but let me give you a valid example, as your code has some syntax errors.

function(ddl)
{
   $("<option value='0'>--- Select a value ---</option>").appendTo(ddl);
}

If this way is ok what type do I pass it in as?

Javascript doesn't use types the same way c# or java do. Just pass a variable, similar to the code above.

Upvotes: 1

Blaster
Blaster

Reputation: 9110

If this way is ok what type do I pass it in as?

It should be jQuery element similar to:

var myuniqueddl = $('#myuniqueddl');

Example:

function addOption(el)
{
   $("<option value='0'>--- Select a value ---</option>").appendTo(el);
}

var myuniqueddl = $('#myuniqueddl');
var myuniqueddl2 = $('#myuniqueddl2');

addOption(myuniqueddl);
addOption(myuniqueddl2);

Or directly:

addOption($('#myuniqueddl'));
addOption($('#myuniqueddl2'));

Upvotes: 3

Related Questions