jQuery get value of select onChange
JquerySelectJquery Problem Overview
I was under the impression that I could get the value of a select input by doing this $(this).val(); and applying the onchange parameter to the select field.
It would appear it only works if I reference the ID.
How do I do it using this.
Jquery Solutions
Solution 1 - Jquery
Try this-
$('select').on('change', function() {
alert( this.value );
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select>
<option value="1">One</option>
<option value="2">Two</option>
</select>
You can also reference with onchange event-
function getval(sel)
{
alert(sel.value);
}
<select onchange="getval(this);">
<option value="1">One</option>
<option value="2">Two</option>
</select>
Solution 2 - Jquery
> I was under the impression that I could get the value of a select > input by doing this $(this).val();
This works if you subscribe unobtrusively (which is the recommended approach):
$('#id_of_field').change(function() {
// $(this).val() will work here
});
if you use onselect and mix markup with script you need to pass a reference to the current element:
onselect="foo(this);"
and then:
function foo(element) {
// $(element).val() will give you what you are looking for
}
Solution 3 - Jquery
This is helped for me.
For select:
$('select_tags').on('change', function() {
alert( $(this).find(":selected").val() );
});
For radio/checkbox:
$('radio_tags').on('change', function() {
alert( $(this).find(":checked").val() );
});
Solution 4 - Jquery
Try the event delegation method, this works in almost all cases.
$(document.body).on('change',"#selectID",function (e) {
//doStuff
var optVal= $("#selectID option:selected").val();
});
Solution 5 - Jquery
$('#select_id').on('change', function()
{
alert(this.value); //or alert($(this).val());
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<select id="select_id">
<option value="1">Option 1</option>
<option value="2">Option 2</option>
<option value="3">Option 3</option>
<option value="4">Option 4</option>
</select>
Solution 6 - Jquery
Arrow function has a different scope than function,
this.value will give undefined for an arrow function.
To fix use
$('select').on('change',(event) => {
alert( event.target.value );
});
Solution 7 - Jquery
You can try this (using jQuery)-
$('select').on('change', function()
{
alert( this.value );
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<select>
<option value="1">Option 1</option>
<option value="2">Option 2</option>
<option value="3">Option 3</option>
<option value="4">Option 4</option>
</select>
Or you can use simple Javascript like this-
function getNewVal(item)
{
alert(item.value);
}
<select onchange="getNewVal(this);">
<option value="1">Option 1</option>
<option value="2">Option 2</option>
<option value="3">Option 3</option>
<option value="4">Option 4</option>
</select>
Solution 8 - Jquery
$('#select-id').change(function() {
console.log($(this).val());
});
Solution 9 - Jquery
jQuery get value of select html elements using on Change event
$(document).ready(function () {
$('body').on('change','#select_box', function() {
$('#show_only').val(this.value);
});
});
<!DOCTYPE html>
<html>
<title>jQuery Select OnChnage Method</title>
<head>
<script src="https://code.jquery.com/jquery-3.3.1.min.js"></script>
</head>
<body>
<select id="select_box">
<option value="">Select One</option>
<option value="One">One</option>
<option value="Two">Two</option>
<option value="Three">Three</option>
<option value="Four">Four</option>
<option value="Five">Five</option>
</select>
<br><br>
<input type="text" id="show_only" disabled="">
</body>
</html>
Solution 10 - Jquery
This is what worked for me. Tried everything else with no luck:
<html>
<head>
<title>Example: Change event on a select</title>
<script type="text/javascript">
function changeEventHandler(event) {
alert('You like ' + event.target.value + ' ice cream.');
}
</script>
</head>
<body>
<label>Choose an ice cream flavor: </label>
<select size="1" onchange="changeEventHandler(event);">
<option>chocolate</option>
<option>strawberry</option>
<option>vanilla</option>
</select>
</body>
</html>
Taken from Mozilla
Solution 11 - Jquery
For all selects, invoke this function.
$('select').on('change', function()
{
alert( this.value );
});
For only one select:
$('#select_id')
Solution 12 - Jquery
Look for jQuery site
HTML:
<form>
<input class="target" type="text" value="Field 1">
<select class="target">
<option value="option1" selected="selected">Option 1</option>
<option value="option2">Option 2</option>
</select>
</form>
<div id="other">
Trigger the handler
</div>
JAVASCRIPT:
$( ".target" ).change(function() {
alert( "Handler for .change() called." );
});
jQuery's example:
To add a validity test to all text input elements:
$( "input[type='text']" ).change(function() {
// Check input( $( this ).val() ) for validity here
});
Solution 13 - Jquery
jQuery(document).ready(function(){
jQuery("#id").change(function() {
var value = jQuery(this).children(":selected").attr("value");
alert(value);
});
})
Solution 14 - Jquery
Let me share an example which I developed with BS4, thymeleaf and Spring boot.
I am using two SELECTs, where the second ("subtopic") gets filled by an AJAX call based on the selection of the first("topic").
First, the thymeleaf snippet:
<div class="form-group">
<label th:for="topicId" th:text="#{label.topic}">Topic</label>
<select class="custom-select"
th:id="topicId" th:name="topicId"
th:field="*{topicId}"
th:errorclass="is-invalid" required>
<option value="" selected
th:text="#{option.select}">Select
</option>
<optgroup th:each="topicGroup : ${topicGroups}"
th:label="${topicGroup}">
<option th:each="topicItem : ${topics}"
th:if="${topicGroup == topicItem.grp} "
th:value="${{topicItem.baseIdentity.id}}"
th:text="${topicItem.name}"
th:selected="${{topicItem.baseIdentity.id==topicId}}">
</option>
</optgroup>
<option th:each="topicIter : ${topics}"
th:if="${topicIter.grp == ''} "
th:value="${{topicIter.baseIdentity.id}}"
th:text="${topicIter.name}"
th:selected="${{topicIter.baseIdentity?.id==topicId}}">
</option>
</select>
<small id="topicHelp" class="form-text text-muted"
th:text="#{label.topic.tt}">select</small>
</div><!-- .form-group -->
<div class="form-group">
<label for="subtopicsId" th:text="#{label.subtopicsId}">subtopics</label>
<select class="custom-select"
id="subtopicsId" name="subtopicsId"
th:field="*{subtopicsId}"
th:errorclass="is-invalid" multiple="multiple">
<option value="" disabled
th:text="#{option.multiple.optional}">Select
</option>
<option th:each="subtopicsIter : ${subtopicsList}"
th:value="${{subtopicsIter.baseIdentity.id}}"
th:text="${subtopicsIter.name}">
</option>
</select>
<small id="subtopicsHelp" class="form-text text-muted"
th:unless="${#fields.hasErrors('subtopicsId')}"
th:text="#{label.subtopics.tt}">select</small>
<small id="subtopicsIdError" class="invalid-feedback"
th:if="${#fields.hasErrors('subtopicsId')}"
th:errors="*{subtopicsId}">Errors</small>
</div><!-- .form-group -->
I am iterating over a list of topics that is stored in the model context, showing all groups with their topics, and after that all topics that do not have a group. BaseIdentity is an @Embedded composite key BTW.
Now, here's the jQuery that handles changes:
$('#topicId').change(function () {
selectedOption = $(this).val();
if (selectedOption === "") {
$('#subtopicsId').prop('disabled', 'disabled').val('');
$("#subtopicsId option").slice(1).remove(); // keep first
} else {
$('#subtopicsId').prop('disabled', false)
var orig = $(location).attr('origin');
var url = orig + "/getsubtopics/" + selectedOption;
$.ajax({
url: url,
success: function (response) {
var len = response.length;
$("#subtopicsId option[value!='']").remove(); // keep first
for (var i = 0; i < len; i++) {
var id = response[i]['baseIdentity']['id'];
var name = response[i]['name'];
$("#subtopicsId").append("<option value='" + id + "'>" + name + "</option>");
}
},
error: function (e) {
console.log("ERROR : ", e);
}
});
}
}).change(); // and call it once defined
The initial call of change() makes sure it will be executed on page re-load or if a value has been preselected by some initialization in the backend.
BTW: I am using "manual" form validation (see "is-valid"/"is-invalid"), because I (and users) didn't like that BS4 marks non-required empty fields as green. But that's byond scope of this Q and if you are interested then I can post it also.
Solution 15 - Jquery
Note that if these are not working, it might be because the DOM has not loaded and your element was not found yet.
To fix, put the script at the end of body or use document ready
$.ready(function() {
$("select").on('change', function(ret) {
console.log(ret.target.value)
}
})
Solution 16 - Jquery
only with JS
let select=document.querySelectorAll('select')
select.forEach(function(el) {
el.onchange = function(){
alert(this.value);
}}
)
Solution 17 - Jquery
I want to add, who needs full custom header functionality
function addSearchControls(json) {
$("#tblCalls thead").append($("#tblCalls thead tr:first").clone());
$("#tblCalls thead tr:eq(1) th").each(function (index) {
// For text inputs
if (index != 1 && index != 2) {
$(this).replaceWith('<th><input type="text" placeholder=" ' + $(this).html() + ' ara"></input></th>');
var searchControl = $("#tblCalls thead tr:eq(1) th:eq(" + index + ") input");
searchControl.on("keyup", function () {
table.column(index).search(searchControl.val()).draw();
})
}
// For DatePicker inputs
else if (index == 1) {
$(this).replaceWith('<th><input type="text" id="datepicker" placeholder="' + $(this).html() + ' ara" class="tblCalls-search-date datepicker" /></th>');
$('.tblCalls-search-date').on('keyup click change', function () {
var i = $(this).attr('id'); // getting column index
var v = $(this).val(); // getting search input value
table.columns(index).search(v).draw();
});
$(".datepicker").datepicker({
dateFormat: "dd-mm-yy",
altFieldTimeOnly: false,
altFormat: "yy-mm-dd",
altTimeFormat: "h:m",
altField: "#tarih-db",
monthNames: ["Ocak", "Şubat", "Mart", "Nisan", "Mayıs", "Haziran", "Temmuz", "Ağustos", "Eylül", "Ekim", "Kasım", "Aralık"],
dayNamesMin: ["Pa", "Pt", "Sl", "Ça", "Pe", "Cu", "Ct"],
firstDay: 1,
dateFormat: "yy-mm-dd",
showOn: "button",
showAnim: 'slideDown',
showButtonPanel: true,
autoSize: true,
buttonImage: "http://jqueryui.com/resources/demos/datepicker/images/calendar.gif",
buttonImageOnly: false,
buttonText: "Tarih Seçiniz",
closeText: "Temizle"
});
$(document).on("click", ".ui-datepicker-close", function () {
$('.datepicker').val("");
table.columns(5).search("").draw();
});
}
// For DropDown inputs
else if (index == 2) {
$(this).replaceWith('<th><select id="filter_comparator" class="styled-select yellow rounded"><option value="select">Seç</option><option value="eq">=</option><option value="gt">>=</option><option value="lt"><=</option><option value="ne">!=</option></select><input type="text" id="filter_value"></th>');
var selectedOperator;
$('#filter_comparator').on('change', function () {
var i = $(this).attr('id'); // getting column index
var v = $(this).val(); // getting search input value
selectedOperator = v;
if(v=="select")
table.columns(index).search('select|0').draw();
$('#filter_value').val("");
});
$('#filter_value').on('keyup click change', function () {
var keycode = (event.keyCode ? event.keyCode : event.which);
if (keycode == '13') {
var i = $(this).attr('id'); // getting column index
var v = $(this).val(); // getting search input value
table.columns(index).search(selectedOperator + '|' + v).draw();
}
});
}
})
}
Solution 18 - Jquery
i have an example to help in new ideas. i hope this will help anybody.
$('#editpricelist_box').change(function ($e){
$('input[name="edit_unit_price"]').val(parseFloat(this.val()).toFixed(2));
console.log(this.val());
});