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Changing the selected option of an HTML Select element
(14 answers)
Closed 5 years ago.
I try a several ways to make it, but only what I got - two selected items in one time. Also I found on SOF a "solution" - document.getElementById("selection-type").selectedIndex = 2; , but it does not work.
I understand that this is a very simple question, but I really do not know what is I'am missed.
var select = document.body.querySelector('select');
for (var i = 0; i < select.options.length; i++) {
if (select.options[i].selected) {
}
}
select.options[1].selected = false;
var newOption = new Option('Classic', 'Classic');
select.append(newOption);
select.options[2].selected = true;
<select>
<option value="Rock">Storm</option>
<option value="Blues" selected>Rain</option>
</select>
You are confusing attributes and properties. Changing a property is a dynamic action that affects the in-memory object, it doesn't modify the static HTML that the element was originally parsed with. If you want to change the attribute, you need to use setAttribute() or removeAttribute().
var select = document.body.querySelector('select');
// Get the element with the "selected" attribute
console.log("Element with 'selected' HTML attribute: " +
select.querySelector("[selected]").getAttribute("value"));
// Get the element with the "selected" value:
console.log("Element with value property of 'selected': " + select.value);
// Change the value property of the select
console.log("Changing value of select element to 'Rock'");
select.value = "Rock";
// Get the element with the "selected" attribute
console.log("Element with 'selected' HTML attribute: " +
select.querySelector("[selected]").getAttribute("value")); // Still Blues!
// Get the element with the "selected" value:
console.log("But, value of the select element is now: " + select.value); // Now Rock!
// Change which element has the selected attribute
console.log("Switching elment that has the 'selected' attribute...");
select.querySelector("[selected]").removeAttribute("selected");
select.querySelector("[value=Rock]").setAttribute("selected", "selected");
console.log("Element with 'selected' HTML attribute: " +
select.querySelector("[selected]").getAttribute("value"));
console.log(select.options[0])
console.log(select.options[1]);
<select>
<option value="Rock">Storm</option>
<option value="Blues" selected>Rain</option>
</select>
To answer the question in the title, all you need to do is set the desired option as selected. To get current <select> value one should look into the select.value:
let select = document.body.querySelector('select'),
newOption = new Option('Classic', 'Classic');
select.append(newOption);
select.options[2].selected = true;
console.log(select.value);
// Classic
<select>
<option value="Rock">Storm</option>
<option value="Blues" selected>Rain</option>
</select>
Also note selected attribute only marks default selection, and is different than the selected property of the <option>. The attribute simply tells the browser if it should render the option as selected when initially drawing the DOM element or not.
When dealing with <select multiple>, you need to check the .selectedOptions property of the <select> and map it to an array. Example:
let select = document.body.querySelector('select'),
newOption = new Option('Classic', 'Classic');
select.append(newOption);
select.options[2].selected = true;
let values = [].slice.call(select.selectedOptions).map(a => a.value);
console.log(values)
// ["Blues","Classic"]
<select multiple>
<option value="Rock">Storm</option>
<option value="Blues" selected>Rain</option>
</select>
The .selectedOptions is an object which contains the selected options, the length and native methods, such as item() and namedItem(). Do note option groups are not contained.
I have INPUT fields on my form which I want to collect the data input from them and store them in an ARRAY to then feed into a SELECT OPTION This is what I have so far, when it is used in the form it doesnt pick up the value from the INPUT boxes and the SELECT shows 2 empty rows, but has an ID against those rows as when I ouput the SELECT into another INPUT further on in my form it will show either 0 or 1.
How can I get the value input from the INPUT into the SELECT, also how can I then show the SELECTED option afterwards?
var MySelectOptions = [document.getElementById("inpbox1").value, document.getElementById("inpbox2").value];
$.each(MySelectOptions, function(key, value) {
$('#theselectbox').append($("<option/>", {
value: key,
text: value
}));
});
this is how I output from the SELECT, I would normally use the second example, but I don't know how to get the SELECTED Option within the code above
$(function() {
$("#theselectbox").change(function(){
var CustomerName = document.getElementById("theselectbox").value;
$('#customername').val(CustomerName);
});
});
How I normally get the SELECTED Option
$(function() {
$("#theselectbox").change(function(){
var CustomerName = $('option:selected', this).attr('theselectoption');
$('#customername').val(CustomerName);
});
});
You can append a new option with a value to select box as:
$('#theselectbox').append('<option value="'+inputValue+'">'+inputValue+'</option>');
And, you can show the selected option by using its value as:
$('#theselectbox').val(inputValue);
// Here you have the list of inputs, from which you will get values
// I will use classes, you can use ids
var inputs = ["input1", "input2"];
// The select to which you will paste the values
var sselect = $(".select-class");
for(var i = 0; i < inputs.length; i++){
var e = $("." + inputs[i]);
sselect.append("<option>"+ e.val() +"</option>");
}
// Now you can just put value to select
sselect.val("selected_value");
How select value from input
<input type="text" class="js-svalue" placeholder="Select value">
Now js
var input = $(".js-svalue");
input.on("change", function(){
sselect.val(input.val());
});
I have a select field that have have present options and I have a php script check a mysql database and add a select tag to the one currently being used.
I need to find a way to know if the user have changed the select field or not before submitting it.
var Access = document.forms[UIDF]["Access"].value;
var DAccess = document.forms[UIDF]["Access"].defaultIndex; <--- This is my problem. I just need to know how to get the selected option value as this keep changing with every user
<select name="Access">
<option value="0" selected='selected'>Employee</option>
<option value="1">Team Leader</option>
<option value="2">Admin</option>
</select>
The Option tag has a javascript attribute defaultSelected that's set to true if the option had a selected value on page load. Note that this is the option tag and not the select one, so you'll have to loop through the options and check for the attribute.
Something like
var DAccess;
var AccessSelect = document.forms[UIDF]["Access"];
for (var i = 0 ; i<AccessSelect.length ; i++)
{
if (AccessSelect[i].defaultSelected)
DAccess = AccessSelect[i].value;
}
Or, more to the point:
var AccessHasChanged = false;
var AccessSelect = document.forms[UIDF]["Access"];
for (var i = 0 ; i<AccessSelect.length ; i++)
{
if (AccessSelect[i].defaultSelected &&
AccessSelect.value != AccessSelect[i].value)
AccessHasChanged = true;
}
I want to use the value of a HTML dropdown box and create that number of input boxes underneath. I'm hoping I can achieve this on the fly. Also if the value changes it should add or remove appropriately.
What programming language would I need to do this in? I'm using PHP for the overall website.
Here is an example that uses jQuery to achieve your goals:
Assume you have following html:
<div>
<select id="input_count">
<option value="1">1 input</option>
<option value="2">2 inputs</option>
<option value="3">3 inputs</option>
</select>
<div>
<div id="inputs"> </div>
And this is the js code for your task:
$('#input_count').change(function() {
var selectObj = $(this);
var selectedOption = selectObj.find(":selected");
var selectedValue = selectedOption.val();
var targetDiv = $("#inputs");
targetDiv.html("");
for(var i = 0; i < selectedValue; i++) {
targetDiv.append($("<input />"));
}
});
You can simplify this code as follows:
$('#input_count').change(function() {
var selectedValue = $(this).val();
var targetDiv = $("#inputs").html("");
for(var i = 0; i < selectedValue; i++) {
targetDiv.append($("<input />"));
}
});
Here is a working fiddle example: http://jsfiddle.net/melih/VnRBm/
You can read more about jQuery: http://jquery.com/
I would go for jQuery.
To start with look at change(), empty() and append()
http://api.jquery.com/change/
http://api.jquery.com/empty/
http://api.jquery.com/append/
Doing it in javascript is quite easy. Assuming you've got a number and an html element where to insert. You can obtain the parent html element by using document.getElementById or other similar methods. The method assumes the only children of the parentElement is going to be these input boxes. Here's some sample code:
function addInput = function( number, parentElement ) {
// clear all previous children
parentElement.innerHtml = "";
for (var i = 0; i < number; i++) {
var inputEl = document.createElement('input');
inputEl['type'] = 'text';
// set other styles here
parentElement.appendChild(inputEl);
}
}
for the select change event, look here: javascript select input event
you would most likely use javascript(which is what jquery is), here is an example to show you how it can be done to get you on your way
<select name="s" onchange="addTxtInputs(this)" onkeyup="addTxtInputs(this)">
<option value="0">Add</option>
<option value="1">1</option>
<option value="3">3</option>
<option value="7">7</option>
</select>
<div id="inputPlaceHolder"></div>
javascript to dynamically create a selected number of inputs on the fly, based on Mutahhir answer
<script>
function addTxtInputs(o){
var n = o.value; // holds the value from the selected option (dropdown)
var p = document.getElementById("inputPlaceHolder"); // this is to get the placeholder element
p.innerHTML = ""; // clears the contents of the place holder each time the select option is chosen.
// loop to create the number of inputs based apon `n`(selected value)
for (var i=0; i < n; i++) {
var odiv = document.createElement("div"); //create a div so each input can have there own line
var inpt = document.createElement("input");
inpt['type'] = "text"; // the input type is text
inpt['id'] = "someInputId_" + i; // set a id for optional reference
inpt['name'] = "someInputName_" + i; // an unique name for each of the inputs
odiv.appendChild(inpt); // append the each input to a div
p.appendChild(odiv); // append the div and inputs to the placeholder (inputPlaceHolder)
}
}
</script>
I have a dynamically created select option using a javascript function. the select object is
<select name="country" id="country">
</select>
when the js function is executed, the "country" object is
<select name="country" id="country">
<option value="AF">Afghanistan</option>
<option value="AL">Albania</option>
...
<option value="ID">Indonesia</option>
...
<option value="ZW">Zimbabwe</option>
</select>
and displaying "Indonesia" as default selected option. note : there is no selected="selected" attribute in that option.
then I need to set selected="selected" attribute to "Indonesia", and I use this
var country = document.getElementById("country");
country.options[country.options.selectedIndex].setAttribute("selected", "selected");
using firebug, I can see the "Indonesia" option is like this
<option value="ID" selected="selected">Indonesia</option>
but it fails in IE (tested in IE 8).
and then I have tried using jQuery
$( function() {
$("#country option:selected").attr("selected", "selected");
});
it fails both in FFX and IE.
I need the "Indonesia" option to have selected="selected" attribute so when I click reset button, it will select "Indonesia" again.
changing the js function to dynamically create "country" options is not an option. the solution must work both in FFX and IE.
thank you
You're overthinking it:
var country = document.getElementById("country");
country.options[country.options.selectedIndex].selected = true;
Good question. You will need to modify the HTML itself rather than rely on DOM properties.
var opt = $("option[val=ID]"),
html = $("<div>").append(opt.clone()).html();
html = html.replace(/\>/, ' selected="selected">');
opt.replaceWith(html);
The code grabs the option element for Indonesia, clones it and puts it into a new div (not in the document) to retrieve the full HTML string: <option value="ID">Indonesia</option>.
It then does a string replace to add the attribute selected="selected" as a string, before replacing the original option with this new one.
I tested it on IE7. See it with the reset button working properly here: http://jsfiddle.net/XmW49/
Instead of modifying the HTML itself, you should just set the value you want from the relative option element:
$(function() {
$("#country").val("ID");
});
In this case "ID" is the value of the option "Indonesia"
So many wrong answers!
To specify the value that a form field should revert to upon resetting the form, use the following properties:
Checkbox or radio button: defaultChecked
Any other <input> control: defaultValue
Option in a drop down list: defaultSelected
So, to specify the currently selected option as the default:
var country = document.getElementById("country");
country.options[country.selectedIndex].defaultSelected = true;
It may be a good idea to set the defaultSelected value for every option, in case one had previously been set:
var country = document.getElementById("country");
for (var i = 0; i < country.options.length; i++) {
country.options[i].defaultSelected = i == country.selectedIndex;
}
Now, when the form is reset, the selected option will be the one you specified.
// get the OPTION we want selected
var $option = $('#SelectList').children('option[value="'+ id +'"]');
// and now set the option we want selected
$option.attr('selected', true);
What you want to do is set the selectedIndex attribute of the select box.
country.options.selectedIndex = index_of_indonesia;
Changing the 'selected' attribute will generally not work in IE. If you really want the behavior you're describing, I suggest you write a custom javascript reset function to reset all the other values in the form to their default.
This works in FF, IE9
var x = document.getElementById("country").children[2];
x.setAttribute("selected", "selected");
Make option defaultSelected
HTMLOptionElement.defaultSelected = true; // JS
$('selector').prop({defaultSelected: true}); // jQuery
HTMLOptionElement MDN
If the SELECT element is already added to the document (statically or dynamically), to set an option to Attribute-selected and to make it survive a HTMLFormElement.reset() - defaultSelected is used:
const EL_country = document.querySelector('#country');
EL_country.value = 'ID'; // Set SELECT value to 'ID' ("Indonesia")
EL_country.options[EL_country.selectedIndex].defaultSelected = true; // Add Attribute selected to Option Element
document.forms[0].reset(); // "Indonesia" is still selected
<form>
<select name="country" id="country">
<option value="AF">Afghanistan</option>
<option value="AL">Albania</option>
<option value="HR">Croatia</option>
<option value="ID">Indonesia</option>
<option value="ZW">Zimbabwe</option>
</select>
</form>
The above will also work if you build the options dynamically, and than (only afterwards) you want to set one option to be defaultSelected.
const countries = {
AF: 'Afghanistan',
AL: 'Albania',
HR: 'Croatia',
ID: 'Indonesia',
ZW: 'Zimbabwe',
};
const EL_country = document.querySelector('#country');
// (Bad example. Ideally use .createDocumentFragment() and .appendChild() methods)
EL_country.innerHTML = Object.keys(countries).reduce((str, key) => str += `<option value="${key}">${countries[key]}</option>`, '');
EL_country.value = 'ID';
EL_country.options[EL_country.selectedIndex].defaultSelected = true;
document.forms[0].reset(); // "Indonesia" is still selected
<form>
<select name="country" id="country"></select>
</form>
Make option defaultSelected while dynamically creating options
To make an option selected while populating the SELECT Element, use the Option() constructor MDN
var optionElementReference = new Option(text, value, defaultSelected, selected);
const countries = {
AF: 'Afghanistan',
AL: 'Albania',
HR: 'Croatia',
ID: 'Indonesia', // <<< make this one defaultSelected
ZW: 'Zimbabwe',
};
const EL_country = document.querySelector('#country');
const DF_options = document.createDocumentFragment();
Object.keys(countries).forEach(key => {
const isIndonesia = key === 'ID'; // Boolean
DF_options.appendChild(new Option(countries[key], key, isIndonesia, isIndonesia))
});
EL_country.appendChild(DF_options);
document.forms[0].reset(); // "Indonesia" is still selected
<form>
<select name="country" id="country"></select>
</form>
In the demo above Document.createDocumentFragment is used to prevent rendering elements inside the DOM in a loop. Instead, the fragment (containing all the Options) is appended to the Select only once.
SELECT.value vs. OPTION.setAttribute vs. OPTION.selected vs. OPTION.defaultSelected
Although some (older) browsers interpret the OPTION's selected attribute as a "string" state, the WHATWG HTML Specifications html.spec.whatwg.org state that it should represent a Boolean selectedness
The selectedness of an option element is a boolean state, initially false. Except where otherwise specified, when the element is created, its selectedness must be set to true if the element has a selected attribute.
html.spec.whatwg.org - Option selectedness
one can correctly deduce that just the name selected in <option value="foo" selected> is enough to set a truthy state.
Comparison test of the different methods
const EL_select = document.querySelector('#country');
const TPL_options = `
<option value="AF">Afghanistan</option>
<option value="AL">Albania</option>
<option value="HR">Croatia</option>
<option value="ID">Indonesia</option>
<option value="ZW">Zimbabwe</option>
`;
// https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver/MutationObserver
const mutationCB = (mutationsList, observer) => {
mutationsList.forEach(mu => {
const EL = mu.target;
if (mu.type === 'attributes') {
return console.log(`* Attribute ${mu.attributeName} Mutation. ${EL.value}(${EL.text})`);
}
});
};
// (PREPARE SOME TEST FUNCTIONS)
const testOptionsSelectedByProperty = () => {
const test = 'OPTION with Property selected:';
try {
const EL = [...EL_select.options].find(opt => opt.selected);
console.log(`${test} ${EL.value}(${EL.text}) PropSelectedValue: ${EL.selected}`);
} catch (e) {
console.log(`${test} NOT FOUND!`);
}
}
const testOptionsSelectedByAttribute = () => {
const test = 'OPTION with Attribute selected:'
try {
const EL = [...EL_select.options].find(opt => opt.hasAttribute('selected'));
console.log(`${test} ${EL.value}(${EL.text}) AttrSelectedValue: ${EL.getAttribute('selected')}`);
} catch (e) {
console.log(`${test} NOT FOUND!`);
}
}
const testSelect = () => {
console.log(`SELECT value:${EL_select.value} selectedIndex:${EL_select.selectedIndex}`);
}
const formReset = () => {
EL_select.value = '';
EL_select.innerHTML = TPL_options;
// Attach MutationObserver to every Option to track if Attribute will change
[...EL_select.options].forEach(EL_option => {
const observer = new MutationObserver(mutationCB);
observer.observe(EL_option, {attributes: true});
});
}
// -----------
// LET'S TEST!
console.log('\n1. Set SELECT value');
formReset();
EL_select.value = 'AL'; // Constatation: MutationObserver did NOT triggered!!!!
testOptionsSelectedByProperty();
testOptionsSelectedByAttribute();
testSelect();
console.log('\n2. Set HTMLElement.setAttribute()');
formReset();
EL_select.options[2].setAttribute('selected', true); // MutationObserver triggers
testOptionsSelectedByProperty();
testOptionsSelectedByAttribute();
testSelect();
console.log('\n3. Set HTMLOptionElement.defaultSelected');
formReset();
EL_select.options[3].defaultSelected = true; // MutationObserver triggers
testOptionsSelectedByProperty();
testOptionsSelectedByAttribute();
testSelect();
console.log('\n4. Set SELECT value and HTMLOptionElement.defaultSelected');
formReset();
EL_select.value = 'ZW'
EL_select.options[EL_select.selectedIndex].defaultSelected = true; // MutationObserver triggers
testOptionsSelectedByProperty();
testOptionsSelectedByAttribute();
testSelect();
/* END */
console.log('\n*. Getting MutationObservers out from call-stack...');
<form>
<select name="country" id="country"></select>
</form>
Although the test 2. using .setAttribute() seems at first the best solution since both the Element Property and Attribute are unison, it can lead to confusion, specially because .setAttribute expects two parameters:
EL_select.options[1].setAttribute('selected', false);
// <option value="AL" selected="false"> // But still selected!
will actually make the option selected
Should one use .removeAttribute() or perhaps .setAttribute('selected', ???) to another value? Or should one read the state by using .getAttribute('selected') or by using .hasAttribute('selected')?
Instead test 3. (and 4.) using defaultSelected gives the expected results:
Attribute selected as a named Selectedness state.
Property selected on the Element Object, with a Boolean value.
select = document.getElementById('selectId');
var opt = document.createElement('option');
opt.value = 'value';
opt.innerHTML = 'name';
opt.selected = true;
select.appendChild(opt);
// Get <select> object
var sel = $('country');
// Loop through and look for value match, then break
for(i=0;i<sel.length;i++) { if(sel.value=="ID") { break; } }
// Select index
sel.options.selectedIndex = i;
Begitu loh.
This should work.
$("#country [value='ID']").attr("selected","selected");
If you have function calls bound to the element just follow it with something like
$("#country").change();
You could search all the option values until it finds the correct one.
var defaultVal = "Country";
$("#select").find("option").each(function () {
if ($(this).val() == defaultVal) {
$(this).prop("selected", "selected");
}
});
Vanilla JS
Use this for Vanilla Javascript, keeping in mind that you can feed the example "numbers" array with any data from a fetch function (for example).
The initial HTML code:
<label for="the_selection">
<select name="the_selection" id="the_selection_id">
<!-- Empty Selection -->
</select>
</label>
Some values select tag:
const selectionList = document.getElementById('the_selection_id');
const numbers = ['1','3','5'];
numbers.forEach(number => {
const someOption = document.createElement('option');
someOption.setAttribute('value', number);
someOption.innerText = number;
if (number == '3') someOption.defaultSelected = true;
selectionList.appendChild(someOption);
})
You'll get:
<label for="the_selection">
<select name="the_selection" id="the_selection_id">
<!-- Empty Selection -->
<option value="1">1</option>
<option value="3" selected>3</option>
<option value="5">5</option>
</select>
</label>
You can solve this on ES6 like this:
var defaultValue = "ID";
[...document.getElementById('country').options].map(e => e.selected = (e.value == defaultValue));
I haven't test in other browsers but in Chrome works just fine.
...document.getElementById('country').options using the spread operator you cast options as an array.
.map allows you to apply a function to each element of your array.
e represents each <option> element of your object so you can access its attributes like .select and .value as getter and setter.
Because you .select receives a boolean option you want to assign when its value is equal to your default value.
To set the input option at run time try setting the 'checked' value. (even if it isn't a checkbox)
elem.checked=true;
Where elem is a reference to the option to be selected.
So for the above issue:
var country = document.getElementById("country");
country.options[country.options.selectedIndex].checked=true;
This works for me, even when the options are not wrapped in a .
If all of the tags share the same name, they should uncheck when the new one is checked.
Realize this is an old question, but with the newer version of JQuery you can now do the following:
$("option[val=ID]").prop("selected",true);
This accomplishes the same thing as Box9's selected answer in one line.
The ideas on this page were helpful, yet as ever my scenario was different. So, in modal bootstrap / express node js / aws beanstalk, this worked for me:
var modal = $(this);
modal.find(".modal-body select#cJourney").val(vcJourney).attr("selected","selected");
Where my select ID = "cJourney" and the drop down value was stored in variable: vcJourney
I was trying something like this using the $(...).val() function, but the function did not exist. It turns out that you can manually set the value the same way you do it for an <input>:
// Set value to Indonesia ("ID"):
$('#country').value = 'ID'
...and it get's automatically updated in the select. Works on Firefox at least; you might want to try it out in the others.
To set value in JavaScript using set attribute , for selected option tag
var newvalue = 10;
var x = document.getElementById("optionid").selectedIndex;
document.getElementById("optionid")[x].setAttribute('value', newvalue);