I have an input form that lets me select from multiple options, and do something when the user changes the selection. Eg,
<select onChange="javascript:doSomething();">
<option>A</option>
<option>B</option>
<option>C</option>
</select>
Now, doSomething() only gets triggered when the selection changes.
I want to trigger doSomething() when the user selects any option, possibly the same one again.
I have tried using an "onClick" handler, but that gets triggered before the user starts the selection process.
So, is there a way to trigger a function on every select by the user?
Update:
The answer suggested by Darryl seemed to work, but it doesn't work consistently. Sometimes the event gets triggered as soon as user clicks the drop-down menu, even before the user has finished the selection process!
I needed something exactly the same. This is what worked for me:
<select onchange="doSomething();" onfocus="this.selectedIndex = -1;">
<option>A</option>
<option>B</option>
<option>C</option>
</select>
Supports this:
when the user selects any option, possibly the same one again
Here is the simplest way:
<select name="ab" onchange="if (this.selectedIndex) doSomething();">
<option value="-1">--</option>
<option value="1">option 1</option>
<option value="2">option 2</option>
<option value="3">option 3</option>
</select>
Works both with mouse selection and keyboard Up/Down keys whes select is focused.
I had the same problem when I was creating a design a few months back. The solution I found was to use .live("change", function()) in combination with .blur() on the element you are using.
If you wish to have it do something when the user simply clicks, instead of changing, just replace change with click.
I assigned my dropdown an ID, selected, and used the following:
$(function () {
$("#selected").live("change", function () {
// do whatever you need to do
// you want the element to lose focus immediately
// this is key to get this working.
$('#selected').blur();
});
});
I saw this one didn't have a selected answer, so I figured I'd give my input. This worked excellently for me, so hopefully someone else can use this code when they get stuck.
http://api.jquery.com/live/
Edit: Use the on selector as opposed to .live. See jQuery .on()
Just an idea, but is it possible to put an onclick on each of the <option> elements?
<select>
<option onclick="doSomething(this);">A</option>
<option onclick="doSomething(this);">B</option>
<option onclick="doSomething(this);">C</option>
</select>
Another option could be to use onblur on the select. This will fire anytime the user clicks away from the select. At this point you could determine what option was selected. To have this even trigger at the correct time, the onclick of the option's could blur the field (make something else active or just .blur() in jQuery).
If you really need this to work like this, I would do this (to ensure it works by keyboard and mouse)
Add an onfocus event handler to the select to set the "current" value
Add an onclick event handler to the select to handle mouse changes
Add an onkeypress event handler to the select to handle keyboard changes
Unfortunately the onclick will run multiple times (e.g. on onpening the select... and on selection/close) and the onkeypress may fire when nothing changes...
<script>
function setInitial(obj){
obj._initValue = obj.value;
}
function doSomething(obj){
//if you want to verify a change took place...
if(obj._initValue == obj.value){
//do nothing, no actual change occurred...
//or in your case if you want to make a minor update
doMinorUpdate();
} else {
//change happened
getNewData(obj.value);
}
}
</script>
<select onfocus="setInitial(this);" onclick="doSomething();" onkeypress="doSomething();">
...
</select>
The onclick approach is not entirely bad but as said, it will not be triggered when the value isn't changed by a mouse-click.
It is however possible to trigger the onclick event in the onchange event.
<select onchange="{doSomething(...);if(this.options[this.selectedIndex].onclick != null){this.options[this.selectedIndex].onclick(this);}}">
<option onclick="doSomethingElse(...);" value="A">A</option>
<option onclick="doSomethingElse(..);" value="B">B</option>
<option onclick="doSomethingElse(..);" value="Foo">C</option>
</select>
I know this question is very old now, but for anyone still running into this problem, I have achieved this with my own website by adding an onInput event to my option tag, then in that called function, retrieving the value of that option input.
<select id='dropdown' onInput='myFunction()'>
<option value='1'>1</option>
<option value='2'>2</option>
</select>
<p>Output: </p>
<span id='output'></span>
<script type='text/javascript'>
function myFunction() {
var optionValue = document.getElementById("dropdown").value;
document.getElementById("output").innerHTML = optionValue;
}
</script>
Going to expand on jitbit's answer. I found it weird when you clicked the drop down and then clicked off the drop down without selecting anything. Ended up with something along the lines of:
var lastSelectedOption = null;
DDChange = function(Dd) {
//Blur after change so that clicking again without
//losing focus re-triggers onfocus.
Dd.blur();
//The rest is whatever you want in the change.
var tcs = $("span.on_change_times");
tcs.html(+tcs.html() + 1);
$("span.selected_index").html(Dd.prop("selectedIndex"));
return false;
};
DDFocus = function(Dd) {
lastSelectedOption = Dd.prop("selectedIndex");
Dd.prop("selectedIndex", -1);
$("span.selected_index").html(Dd.prop("selectedIndex"));
return false;
};
//On blur, set it back to the value before they clicked
//away without selecting an option.
//
//This is what is typically weird for the user since they
//might click on the dropdown to look at other options,
//realize they didn't what to change anything, and
//click off the dropdown.
DDBlur = function(Dd) {
if (Dd.prop("selectedIndex") === -1)
Dd.prop("selectedIndex", lastSelectedOption);
$("span.selected_index").html(Dd.prop("selectedIndex"));
return false;
};
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select id="Dd" onchange="DDChange($(this));" onfocus="DDFocus($(this));" onblur="DDBlur($(this));">
<option>1</option>
<option>2</option>
</select>
<br/>
<br/>Selected index: <span class="selected_index"></span>
<br/>Times onchange triggered: <span class="on_change_times">0</span>
This makes a little more sense for the user and allows JavaScript to run every time they select any option including an earlier option.
The downside to this approach is that it breaks the ability to tab onto a drop down and use the arrow keys to select the value. This was acceptable for me since all the users click everything all the time until the end of eternity.
To properly fire an event every time the user selects something(even the same option), you just need to trick the select box.
Like others have said, specify a negative selectedIndex on focus to force the change event. While this does allow you to trick the select box, it won't work after that as long as it still has focus. The simple fix is to force the select box to blur, shown below.
Standard JS/HTML:
<select onchange="myCallback();" onfocus="this.selectedIndex=-1;this.blur();">
<option>A</option>
<option>B</option>
<option>C</option>
</select>
jQuery Plugin:
<select>
<option>A</option>
<option>B</option>
<option>C</option>
</select>
<script type="text/javascript">
$.fn.alwaysChange = function(callback) {
return this.each(function(){
var elem = this;
var $this = $(this);
$this.change(function(){
if(callback) callback($this.val());
}).focus(function(){
elem.selectedIndex = -1;
elem.blur();
});
});
}
$('select').alwaysChange(function(val){
// Optional change event callback,
// shorthand for $('select').alwaysChange().change(function(){});
});
</script>
You can see a working demo here.
first of all u use onChange as an event handler and then use flag variable to make it do the function u want every time u make a change
<select
var list = document.getElementById("list");
var flag = true ;
list.onchange = function () {
if(flag){
document.bgColor ="red";
flag = false;
}else{
document.bgColor ="green";
flag = true;
}
}
<select id="list">
<option>op1</option>
<option>op2</option>
<option>op3</option>
</select>
This may not directly answer your question, but this problem could be solved by simple design level adjustments. I understand this may not be 100% applicable to all use-cases, but I strongly urge you to consider re-thinking your user flow of your application and if the following design suggestion can be implemented.
I decided to do something simple than hacking alternatives for onChange() using other events that were not really meant for this purpose (blur, click, etc.)
The way I solved it:
Simply pre-pend a placeholder option tag such as select that has no value to it.
So, instead of just using the following structure, which requires hack-y alternatives:
<select>
<option>A</option>
<option>B</option>
<option>C</option>
</select>
Consider using this:
<select>
<option selected="selected">Select...</option>
<option>A</option>
<option>B</option>
<option>C</option>
</select>
So, this way, your code is a LOT more simplified and the onChange will work as expected, every time the user decides to select something other than the default value. You could even add the disabled attribute to the first option if you don't want them to select it again and force them to select something from the options, thus triggering an onChange() fire.
At the time of this answer, I'm writing a complex Vue application and I found that this design choice has simplified my code a lot. I spent hours on this problem before I settled down with this solution and I didn't have to re-write a lot of my code. However, if I went with the hacky alternatives, I would have needed to account for the edge cases, to prevent double firing of ajax requests, etc. This also doesn't mess up the default browser behaviour as a nice bonus (tested on mobile browsers as well).
Sometimes, you just need to take a step back and think about the big picture for the simplest solution.
Add an extra option as the first, like the header of a column, which will be the default value of the dropdown button before click it and reset at the end of doSomething(), so when choose A/B/C, the onchange event always trigs, when the selection is State, do nothing and return. onclick is very unstable as many people mentioned before. So all we need to do is to make an initial button label which is different as your true options so the onchange will work on any option.
<select id="btnState" onchange="doSomething(this)">
<option value="State" selected="selected">State</option>
<option value="A">A</option>
<option value="B">B</option>
<option value="C">C</option>
</select>
function doSomething(obj)
{
var btnValue = obj.options[obj.selectedIndex].value;
if (btnValue == "State")
{
//do nothing
return;
}
// Do your thing here
// reset
obj.selectedIndex = 0;
}
Actually, the onclick events will NOT fire when the user uses the keyboard to change the selection in the select control. You might have to use a combination of onChange and onClick to get the behavior you're looking for.
The wonderful thing about the select tag (in this scenario) is that it will grab its value from the option tags.
Try:
<select onChange="javascript:doSomething(this.value);">
<option value="A">A</option>
<option value="B">B</option>
<option value="Foo">C</option>
</select>
Worked decent for me.
What I did when faced with a similar Problem is I added an 'onFocus' to the select box which appends a new generic option ('select an option'or something similar) and default it as the selected option.
So my goal was to be able to select the same value multiple times which essentially overwrites the the onchange() function and turn it into a useful onclick() method.
Based on the suggestions above I came up with this which works for me.
<select name="ab" id="hi" onchange="if (typeof(this.selectedIndex) != undefined) {alert($('#hi').val()); this.blur();}" onfocus="this.selectedIndex = -1;">
<option value="-1">--</option>
<option value="1">option 1</option>
<option value="2">option 2</option>
<option value="3">option 3</option>
</select>
http://jsfiddle.net/dR9tH/19/
2022 VANILLA JAVASCRIPT
...because this is a top hit on Google.
Original Poster did NOT ask for a JQuery solution, yet all answers ONLY demonstrate JQuery or inline SELECT tag event.
Use an event listener with the 'change' event.
const selectDropdown = document.querySelector('select');
selectDropdown.addEventListener('change', function (e) { /* your code */ });
... or call a seperate function:
function yourFunc(e) { /* your code here */ }
const selectDropdown = document.querySelector('select');
selectDropdown.addEventListener('change', yourFunc);
Kindly note that Event Handlers are not supported for the OPTION tag on IE, with a quick thinking..I came up with this solution, try it and give me your feedback:
<script>
var flag = true;
function resetIndex(selObj) {
if(flag) selObj.selectedIndex = -1;
flag = true;
}
function doSomething(selObj) {
alert(selObj.value)
flag = false;
}
</script>
<select onchange="doSomething(this)" onclick="resetIndex(this)">
<option value="A">A</option>
<option value="B">B</option>
<option value="C">C</option>
</select>
What I'm doing here actually is resetting the select index so that the onchange event will be triggered always, true that you we lose the selected item when you click and it maybe annoying if your list is long, but it may help you in someway..
use jquery:
<select class="target">
<option>A</option>
<option>B</option>
<option>C</option>
</select>
<script>
$('.target').change(function() { doSomething(); });
</script>
Here's my solution, completely different to any else on here. It uses the mouse position to figure out if an option was clicked as oppose to clicking on the select box to open the dropdown. It makes use of the event.screenY position as this is the only reliable cross browser variable. A hover event has to be attached first so it can figure out the controls position relative to the screen before the click event.
var select = $("select");
var screenDif = 0;
select.bind("hover", function (e) {
screenDif = e.screenY - e.clientY;
});
select.bind("click", function (e) {
var element = $(e.target);
var eventHorizon = screenDif + element.offset().top + element.height() - $(window).scrollTop();
if (e.screenY > eventHorizon)
alert("option clicked");
});
Here is my jsFiddle
http://jsfiddle.net/sU7EV/4/
you should try using option:selected
$("select option:selected").click(doSomething);
What works for me:
<select id='myID' onchange='doSomething();'>
<option value='0' selected> Select Option </option>
<option value='1' onclick='if (!document.getElementById("myID").onchange()) doSomething();' > A </option>
<option value='2' onclick='if (!document.getElementById("myID").onchange()) doSomething();' > B </option>
</select>
In that way, onchange calls 'doSomething()' when the option changes, and
onclick calls 'doSomething()' when onchange event is false, in other words, when you select the same option
Try this (event triggered exactly when you select option, without option changing):
$("select").mouseup(function() {
var open = $(this).data("isopen");
if(open) {
alert('selected');
}
$(this).data("isopen", !open);
});
http://jsbin.com/dowoloka/4
The one True answer is to not use the select field (if you need to do something when you re-select same answer.)
Create a dropdown menu with conventional div, button, show/hide menu. Link: https://www.w3schools.com/howto/howto_js_dropdown.asp
Could have been avoided had one been able to add event listeners to options. If there had been an onSelect listener for select element. And if clicking on the select field didn't aggravatingly fire off mousedown, mouseup, and click all at the same time on mousedown.
<script>
function abc(selectedguy) {
alert(selectedguy);
}
</script>
<select onchange="abc(this.selectedIndex);">
<option>option one</option>
<option>option two</option>
</select>
Here you have the index returned, and in the js code you can use this return with one switch or anything you want.
Try this:
<select id="nameSelect" onfocus="javascript:document.getElementById('nameSelect').selectedIndex=-1;" onchange="doSomething(this);">
<option value="A">A</option>
<option value="B">B</option>
<option value="C">C</option>
</select>
A long while ago now but in reply to the original question, would this help ?
Just put onClick into the SELECT line.
Then put what you want each OPTION to do in the OPTION lines.
ie:
<SELECT name="your name" onClick>
<option value ="Kilometres" onClick="YourFunction()">Kilometres
-------
-------
</SELECT>
<select name="test[]"
onchange="if(this.selectedIndex < 1){this.options[this.selectedIndex].selected = !1}">
<option>1</option>
<option>2</option>
<option>3</option>
</select>
I had faced a similar need and ended up writing a angularjs directive for the same -
guthub link - angular select
Used element[0].blur(); to remove the focus off the select tag. Logic is to trigger this blur on second click of the dropdown.
as-select gets triggered even when user selects the same value in the dropdown.
DEMO - link
There are a few things you want to do here to make sure it remembers older values and triggers an onchange event even if the same option is selected again.
The first thing you want is a regular onChange event:
$("#selectbox").on("change", function(){
console.log($(this).val());
doSomething();
});
To have the onChange event trigger even when the same option is selected again, you can unset selected option when the dropdown receives focus by setting it to an invalid value. But you also want to store the previously selected value to restore it in case the user does not select any new option:
prev_select_option = ""; //some kind of global var
$("#selectbox").on("focus", function(){
prev_select_option = $(this).val(); //store currently selected value
$(this).val("unknown"); //set to an invalid value
});
The above code will allow you to trigger onchange even if the same value is selected. However, if the user clicks outside the select box, you want to restore the previous value. We do it on onBlur:
$("#selectbox").on("blur", function(){
if ($(this).val() == null) {
//because we previously set an invalid value
//and user did not select any option
$(this).val(prev_select_option);
}
});
I've been using a nice, elegant plugin called DropKick for my webapp http://jamielottering.github.com/DropKick/, and I seem to be having a slight issue with it and am not sure how to go about trying to fix it. I am trying to programmatically change the value of the select drop down menu. Below is a description of my issue, and a link to JSFiddle.
HTML:
<select id="start" class="timePreference">
<option value="Choose">Choose</option>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<option value="9">9</option>
<option value="10">10</option>
<option value="11">11</option>
<option value="12">12</option>
</select>
jQuery:
$('.timePreference').dropkick();
$('#someDiv').click(function() {
$('#start').val("1");
alert($('#start').val());
);
When I show the value in alert, it shows as one, however when I look at the labels on the option it stays at the default or whatever it was prior to the change.
For example, if my default was "Choose" and I click someDiv, then alert will show "1", so it changing, but the select dropdown will still show "Choose". Any suggestions. I may just be missing something small, not sure.
FSFiddle: http://jsfiddle.net/kdp8791/aNS9R/61/
working demo : With Commnet http://jsfiddle.net/aNS9R/218/ && without comments only 7 lines needed: http://jsfiddle.net/aNS9R/220/
-phew-
So, to start with I tried Change event [of dropkick] with in drop kick but its only for the change event within select and not from external element binding. i.e. in your case change button.
So; this is what I have done:
Explanation (if you interested)
I used firebug to inspect the variable and found that dropkick marshal your existing select with nice styling now when you used $('#timePreference option:selected').val("1"); dropkick actually did changed the selected value with in your element with id=timePreference but the div and ul and li styling which is created by dropkick is not changed yet.
For the chosen span it has a class .dk_label and for the current (green color) is given by .dk_option_current class.
Please Note I pretty much read the plugin and figure out what is happening from here: https://github.com/JamieLottering/DropKick/blob/master/jquery.dropkick-1.0.0.js
If you wish to use firebug and see how elements are se use this link : http://jsfiddle.net/aNS9R/218/show/ and play around with your inspect mode, you will see dropkick styling and how it works.
JQuery code
$(document).ready(function() {
$('#timePreference').dropkick();
$('#go').click(function(){
// Assign slected option value to your select here -
// you can also make it something like this but your existing cdoe works anyways $("select_id option[value='3']").attr('selected','selected');
$('#timePreference').val("1");
//Now assign the select text value to the dropkick added element.
//If you will use firebug you can see the nice <div>, <ul> & <li> structure which morph your dropdown.
$('.dk_label').text(1);
// further if you want green color to be selected. class=dk_option_current does that
// You need to loop through the dropkick hierachy
$(".dk_options_inner li").each(function(){
$(this).removeAttr('class');
if ($(this).text() == "1"){
$(this).attr('class', 'dk_option_current');
}
});
});
});
Hope this helps you mate, cheers!
HTML
<select id="timePreference">
<option value="Choose" selected="selected">Choose</option>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<option value="9">9</option>
<option value="10">10</option>
<option value="11">11</option>
<option value="12">12</option>
</select>
<input name="go" id="go" type="button" value="change" />
You can set the dropkick value programmatically by jQuery trigger of a click event on the selected dropkick option.
$option = $('#dk_container_'+ k +' .dk_options a[data-dk-dropdown-value="'+ v +'"]');
$option.trigger("click");
Here k is the select id or name, and v is the selected value.
The click event of dropkick will automatically take care of setting the classes of options to reflect the change.
I'm a bit late answering this but I have recently come across the same issue - updating a Dropkick DDL after it has been created. I have taken Tats_innit's code and modified it slightly, creating a function that allows you to simply pass in the ID of the select element and the value you want to change it to.
function updateDropkickDDL(id, value) {
//Get the select element and dropkick container
var select = $(id);
var dk = select.prev('.dk_container');
//Set the value of the select
select.val(value);
//Loop through the dropkick options
dk.find('.dk_options_inner').children("li").each(function () {
var li = $(this);
var link = li.children('a');
//Remove the 'current' class if it has it
li.removeClass('dk_option_current');
//If the option has the value we passed in
if (link.data('dk-dropdown-value') == value) {
//Set the 'current' class on the option
li.addClass('dk_option_current');
//Set the text of the dropkick element
dk.find('.dk_label').text(link.text());
}
});
}
You should now be able to simply call updateDropkickDDL on the click of a button or similar, for example, to set the value of the dropdown in your question to 1 you would use:
$(document).ready(function(){
$('#start').dropkick();
$('#someDiv').click(function(){
updateDropkickDDL('#start', 1)
});
}
This function also allows the use of multiple dropkick dropdown lists on the page, only updating the specified dropdown.
I hope this will help someone else encountering this issue.
I know this question is a few months old, but for anyone looking this up later I wanted to add this link to a pull request on the DropKick repository that adds in a "reverse sync" option that updates the custom dropdown menu whenever the underlying select object changes. That allows you to just update the select object in your code and the DropKick custom dropdown updates on the "change" event.
https://github.com/JamieLottering/DropKick/pull/27
best way to change value
just add to jquery.dropkick-X.X.X.js
after
methods.reset = function () {
...
};
this code
// change value of current select
// usage: $("...").dropkick('select', select_value);
methods.select = function (value) {
for (var i = 0, l = lists.length; i < l; i++) {
var
listData = lists[i].data('dropkick'),
$dk = listData.$dk
;
if ($(this)[0] == $dk.next()[0]){
var $current = $($dk.find('li a[data-dk-dropdown-value="' + value + '"]')[0]).closest('li');
$dk.find('.dk_label').text(listData.label);
$dk.find('.dk_options_inner').animate({ scrollTop: 0 }, 0);
_setCurrent($current, $dk);
_updateFields($current, $dk, true);
var data = $dk.data('dropkick');
var $select = data.$select;
$select.val(value);
if ($.browser.msie)
$current.find('a').trigger('mousedown');
else
$current.find('a').trigger('click');
break;
}
}
};
usage: $("...").dropkick('select', select_value);
pros
- native change state of dropkick object
- change selected option in original select
- trigger event, useful if you listen "change" state
cons
- need to change original library
- long code :)
I have two drop-down lists populated from an array of same dates stored in a database. I want to use javascript or jquery to change the second drop-down list based on the selection from the first list. So an example would be if the user selects 03/03/2012 in the first, start date list, then I'd like the second list to only show or allow future dates within the array. 3/3, 3/2 and 3/1 would either be greyed out or removed and 3/4, 3/5 would remain as selectable options. Can anyone help with the javascript coding or make another recommendation?
<select id='start_date' name='data[sDate]' title='Use the drop list'>
<option value="" selected="selected"> </option>
<option value="03/05/2012">03/05/2012</option>
<option value="03/04/2012">03/04/2012</option>
<option value="03/03/2012">03/03/2012</option>
<option value="03/02/2012">03/02/2012</option>
<option value="03/01/2012">03/01/2012</option>
</select>
<select id='end_date' name='data[eDate]' title='Use the drop list'>
<option value="" selected="selected"> </option>
<option value="03/05/2012">03/05/2012</option>
<option value="03/04/2012">03/04/2012</option>
<option value="03/03/2012">03/03/2012</option>
<option value="03/02/2012">03/02/2012</option>
<option value="03/01/2012">03/01/2012</option>
</select>
With your actual example, if the two lists are exactly the same then it's pretty simple if you work with index(). Look http://jsfiddle.net/elclanrs/7YrqY/
$('#start_date').change(function(){
var $selected = $(this).find('option:selected');
$('#end_date')
.find('option')
.prop('disabled', false)
.eq($selected.index()-1)
.nextAll()
.prop('disabled', true);
});
Here's a few different solutions, including server side. This is a common scenario and I'm sure you could find more examples on this site if you searched a bit more.
http://css-tricks.com/dynamic-dropdowns/
using jQuery
$(function(){ //when the page is loaded
$("#start_date").change(function(){ //register a anonymous function that will be called when the element with id=start_date changes his values
var start = $(this).val(); //gets the value of the element
$("#end_date option").each(function(i){//for each option of end_date
if(new Date($(this).val()).getTime() < new Date(start).getTime()){ //if the date of the element is before the start
$(this).hide(); //hide the element
}else{
$(this).show(); //shows the element
}
});
});
});
Ive not tested but is something like that
I've googled and tried a number of ways to do this but none work for me so far. What I am looking for is quite simple: I want to be able to tell whether a dropdown has a selected value or not. The problem is that selectedIndex, :selected, val(), etc. do return results for the following case:
<select>
<option value="123">123</option>
<option value="234">234</option>
</select>
Obviously the browser will display this dropdown with the 123 option being selected but it will be selected only because there are no other options, in reality this dropdown doesn't have a selected value because there is no "selected" property. So basically I am trying to find how to tell apart the above dropdown from this one
<select>
<option selected value="123">123</option>
<option value="234">234</option>
</select>
var hasValue = ($('select > [selected]').length > 0);
Alternatively,
var hasValue = $('select').has('[selected]');
Quick solution:
<select>
<option selected></option>
<option value="123">123</option>
<option value="234">234</option>
</select>
Then see if you have a .val()
The approved answer doesn't seem to work for me.
Here is how I do it to check if all select options are selected:
if($('select option:selected').length > 0) {
/* Do your stuff here */
}
As far as I can tell, there is no functional distinction between your two examples. Essentially, the browser automatically selects the first option.
See, for example, the result of
$('option:selected')
on your first example.
If you really want to prevent this happening, you have two options. The first is to introduce a new, empty element into the select, per Jason's answer. The other option is to deselect the automatically selected value:
$(document).load(function(){
$('option:selected').attr('selected', false);
});
This clears the selection. Any result of $('select').val() that isn't an empty string will therefore be a change by the user.