I have an select option menu which I want to use for multiple functions, but instead of wrapping this code around each function I thought way an I not making a variable outside of it so I can use that. Now I am trying to that with returning the variable and calling that function but it only works the first one and isn't being triggered when I select an other option.
what is the best way to achieve this?
<select id="level_select" onchange="LevelName()">
<option select disabled>Select Level</option>
<option value="2d" id="high_water_pass_1">Highwater Pass 1</option>
<option value="2e" id="high_water_pass_2">Highwater Pass 2</option>
</select>
var name = LevelName();
function LevelName() {
level = $('#level_select').find(":selected").attr("id");
return level;
}
console.log(name);
Here's a working fiddle: https://jsfiddle.net/gdb2xod8/2/.
I really didn't change anything except for the location of the script itself, Click the javascript gear, and you'll notice I've put it in the head
You need to put your script before your html, the head is a good location:
<html>
<head>
<script>
//script here, or better, reference your script in the src attribute
var name = LevelName();
function LevelName() {
level = $('#level_select').find(":selected").attr("id");
console.log(level)
return level;
}
console.log(name);
</script>
</head>
<body>
<select id="level_select" onchange="LevelName()">
<option selected disabled>Select Level</option>
<option value="2d" id="high_water_pass_1">Highwater Pass 1</option>
<option value="2e" id="high_water_pass_2">Highwater Pass 2</option>
</select>
</body>
</html>
Also, I changed your "select" attribute to "selected". Should give you the behavior you're expecting.
You should call console.log inside your function:
function LevelName() {
level = $('#level_select').find(":selected").attr("id");
console.log(level);
return level;
}
Your console.log is triggered once actually.
I want to Modify text contents of dynamically generated drop down list using jQuery. Here is my example:
Drop Down Text look like below:
<select id="s1">
<option data-name="volvo" value="1">1:Volvo</option>
<option data-name="saab" value="2">2:Saab</option>
<option data-name="mercedes" value="3">3:Mercedes</option>
<option data-name="audi" value="4">4:Audi</option>
<option data-name="BMW" value="11">11:BMW</option>
</select>
jQuery:
var previous;
$('#s1').focus(function () {
// Store the current value on focus, before it changes
previous = this.value;
}).change(function() {
//Modify the SelectedOption Display only Number Value
$('#s1').find(':selected').text($('#s1').find(':selected').val());
//Restore the Previous Option : Format 'Number Value : data-name'
alert($("#s1 option[value='"+previous+"']").val());
alert($("#s1 option[value='"+previous+"']").attr('data-name'));
$("#s1 option[value='"+previous+"']").text($("#s1 option[value='"+previous+"']").val() +' '+ $("#s1 option[value='"+previous+"']").attr('data-name'));
});
I also used following attributes :
value: stores number value of that car
data-name: stores the Name of that Car
This is what I want:
Whenever any user select any option, then the selected option text will be modified and removes that Name part: For example: selecting 1:Volvo become 1 only.However if user select another option then the previous option text will be restore back to previous format e.g: 1 becomes 1:Volvo again. That is why i used given attributes to restore format.
I have written a code that works fine if i used alert .But i want to do it without using alert and then it does not work.
Here is my code:
jsfiddle
please help.
You have set data-name and value attributes, so you can easily loop over the options and use those attributes to update the text:
$('#s1').change(function() {
$(this).find('option').each(function(){
$(this).text(
$(this).attr('value')+( $(this).is(':selected') ? '' : ':'+$(this).attr('data-name'))
);
});
});
$('#s1').change(function() {
$(this).find('option').each(function(){
$(this).text(
$(this).attr('value')+( $(this).is(':selected') ? '' : ':'+$(this).attr('data-name'))
);
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select id="s1">
<option data-name="volvo" value="1">1:Volvo</option>
<option data-name="saab" value="2">2:Saab</option>
<option data-name="mercedes" value="3">3:Mercedes</option>
<option data-name="audi" value="4">4:Audi</option>
<option data-name="BMW" value="11">11:BMW</option>
</select>
EDIT (comment)
I'd say that with a normal usage, the code above will have no impact on user experience. It will be slower in a mathematics(?) meaning - negligible differences in execution time, as DOM is modified (each <option> is updated) inside $.each() loop, which isn't the best idea. But nothing that usar can notice.
For the OP example, where only 5 options are involved, it's arguable that updating all of them VS updating only 2, won't make any difference in speed. If there would be hundrets of options, then (speaking about user experience) I, as a user, wouldn't be so glad having so many options to pass through, searching the one I need. So the main issue would be there.
But, if there are any concerns about the above script speed, there's another (a better?) way, without using global flags and loops.
It creates a temporary data-last attribute for identifying previously selected <option> and only two options are modified at a time :
$('#s1').change(function() {
$(this).find('option:selected').attr('data-last','Yes').text(this.value)
.siblings('[data-last]').removeAttr('data-last').text(function(){
return this.value+':'+$(this).attr('data-name');
});
});
$('#s1').change(function() {
$(this).find('option:selected').attr('data-last','Yes').text(this.value)
.siblings('[data-last]').removeAttr('data-last').text(function(){
return this.value+':'+$(this).attr('data-name');
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select id="s1">
<option data-name="volvo" value="1">1:Volvo</option>
<option data-name="saab" value="2">2:Saab</option>
<option data-name="mercedes" value="3">3:Mercedes</option>
<option data-name="audi" value="4">4:Audi</option>
<option data-name="BMW" value="11">11:BMW</option>
</select>
And there's a speed comparison between these two methods (200 options) :
JSFiddle
How do I get the selected value from a dropdown list using JavaScript?
<form>
<select id="ddlViewBy">
<option value="1">test1</option>
<option value="2" selected="selected">test2</option>
<option value="3">test3</option>
</select>
</form>
Given a select element that looks like this:
<select id="ddlViewBy">
<option value="1">test1</option>
<option value="2" selected="selected">test2</option>
<option value="3">test3</option>
</select>
Running this code:
var e = document.getElementById("ddlViewBy");
var value = e.value;
var text = e.options[e.selectedIndex].text;
Results in:
value == 2
text == "test2"
Interactive example:
var e = document.getElementById("ddlViewBy");
function onChange() {
var value = e.value;
var text = e.options[e.selectedIndex].text;
console.log(value, text);
}
e.onchange = onChange;
onChange();
<form>
<select id="ddlViewBy">
<option value="1">test1</option>
<option value="2" selected="selected">test2</option>
<option value="3">test3</option>
</select>
</form>
Plain JavaScript:
var e = document.getElementById("elementId");
var value = e.options[e.selectedIndex].value;
var text = e.options[e.selectedIndex].text;
jQuery:
$("#elementId :selected").text(); // The text content of the selected option
$("#elementId").val(); // The value of the selected option
AngularJS: (http://jsfiddle.net/qk5wwyct):
// HTML
<select ng-model="selectItem" ng-options="item as item.text for item in items">
</select>
<p>Text: {{selectItem.text}}</p>
<p>Value: {{selectItem.value}}</p>
// JavaScript
$scope.items = [{
value: 'item_1_id',
text: 'Item 1'
}, {
value: 'item_2_id',
text: 'Item 2'
}];
var strUser = e.options[e.selectedIndex].value;
This is correct and should give you the value.
Is it the text you're after?
var strUser = e.options[e.selectedIndex].text;
So you're clear on the terminology:
<select>
<option value="hello">Hello World</option>
</select>
This option has:
Index = 0
Value = hello
Text = Hello World
The following code exhibits various examples related to getting/putting of values from input/select fields using JavaScript.
Source Link
Working Javascript & jQuery Demo
<select id="Ultra" onchange="run()"> <!--Call run() function-->
<option value="0">Select</option>
<option value="8">text1</option>
<option value="5">text2</option>
<option value="4">text3</option>
</select><br><br>
TextBox1<br>
<input type="text" id="srt" placeholder="get value on option select"><br>
TextBox2<br>
<input type="text" id="rtt" placeholder="Write Something !" onkeyup="up()">
The following script is getting the value of the selected option and putting it in text box 1
<script>
function run() {
document.getElementById("srt").value = document.getElementById("Ultra").value;
}
</script>
The following script is getting a value from a text box 2 and alerting with its value
<script>
function up() {
//if (document.getElementById("srt").value != "") {
var dop = document.getElementById("srt").value;
//}
alert(dop);
}
</script>
The following script is calling a function from a function
<script>
function up() {
var dop = document.getElementById("srt").value;
pop(dop); // Calling function pop
}
function pop(val) {
alert(val);
}?
</script>
var selectedValue = document.getElementById("ddlViewBy").value;
If you ever run across code written purely for Internet Explorer you might see this:
var e = document.getElementById("ddlViewBy");
var strUser = e.options(e.selectedIndex).value;
Running the above in Firefox et al will give you an 'is not a function' error, because Internet Explorer allows you to get away with using () instead of []:
var e = document.getElementById("ddlViewBy");
var strUser = e.options[e.selectedIndex].value;
The correct way is to use square brackets.
Use:
<select id="Ultra" onchange="alert(this.value)">
<option value="0">Select</option>
<option value="8">text1</option>
<option value="5">text2</option>
<option value="4">text3</option>
</select>
Any input/form field can use a “this” keyword when you are accessing it from inside the element. This eliminates the need for locating a form in the DOM tree and then locating this element inside the form.
There are two ways to get this done either using JavaScript or jQuery.
JavaScript:
var getValue = document.getElementById('ddlViewBy').selectedOptions[0].value;
alert (getValue); // This will output the value selected.
OR
var ddlViewBy = document.getElementById('ddlViewBy');
var value = ddlViewBy.options[ddlViewBy.selectedIndex].value;
var text = ddlViewBy.options[ddlViewBy.selectedIndex].text;
alert (value); // This will output the value selected
alert (text); // This will output the text of the value selected
jQuery:
$("#ddlViewBy:selected").text(); // Text of the selected value
$("#ddlViewBy").val(); // Outputs the value of the ID in 'ddlViewBy'
Beginners are likely to want to access values from a select with the NAME attribute rather than ID attribute. We know all form elements need names, even before they get ids.
So, I'm adding the getElementsByName() solution just for new developers to see too.
NB. names for form elements will need to be unique for your form to be usable once posted, but the DOM can allow a name be shared by more than one element. For that reason consider adding IDs to forms if you can, or be explicit with form element names my_nth_select_named_x and my_nth_text_input_named_y.
Example using getElementsByName:
var e = document.getElementsByName("my_select_with_name_ddlViewBy")[0];
var strUser = e.options[e.selectedIndex].value;
Just use
$('#SelectBoxId option:selected').text(); for getting the text as listed
$('#SelectBoxId').val(); for getting the selected index value
I don't know if I'm the one that doesn't get the question right, but this just worked for me:
Use an onchange() event in your HTML, for example.
<select id="numberToSelect" onchange="selectNum()">
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>
JavaScript
function selectNum() {
var strUser = document.getElementById("numberToSelect").value;
}
This will give you whatever value is on the select dropdown per click.
Using jQuery:
$('select').val();
The previous answers still leave room for improvement because of the possibilities, the intuitiveness of the code, and the use of id versus name. One can get a read-out of three data of a selected option -- its index number, its value and its text. This simple, cross-browser code does all three:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Demo GetSelectOptionData</title>
</head>
<body>
<form name="demoForm">
<select name="demoSelect" onchange="showData()">
<option value="zilch">Select:</option>
<option value="A">Option 1</option>
<option value="B">Option 2</option>
<option value="C">Option 3</option>
</select>
</form>
<p id="firstP"> </p>
<p id="secondP"> </p>
<p id="thirdP"> </p>
<script>
function showData() {
var theSelect = demoForm.demoSelect;
var firstP = document.getElementById('firstP');
var secondP = document.getElementById('secondP');
var thirdP = document.getElementById('thirdP');
firstP.innerHTML = ('This option\'s index number is: ' + theSelect.selectedIndex + ' (Javascript index numbers start at 0)');
secondP.innerHTML = ('Its value is: ' + theSelect[theSelect.selectedIndex].value);
thirdP.innerHTML = ('Its text is: ' + theSelect[theSelect.selectedIndex].text);
}
</script>
</body>
</html>
Live demo: http://jsbin.com/jiwena/1/edit?html,output .
id should be used for make-up purposes. For functional form purposes, name is still valid, also in HTML5, and should still be used. Lastly, mind the use of square versus round brackets in certain places. As was explained before, only (older versions of) Internet Explorer will accept round ones in all places.
Another solution is:
document.getElementById('elementId').selectedOptions[0].value
The simplest way to do this is:
var value = document.getElementById("selectId").value;
You can use querySelector.
E.g.
var myElement = document.getElementById('ddlViewBy');
var myValue = myElement.querySelector('[selected]').value;
Running example of how it works:
var e = document.getElementById("ddlViewBy");
var val1 = e.options[e.selectedIndex].value;
var txt = e.options[e.selectedIndex].text;
document.write("<br />Selected option Value: "+ val1);
document.write("<br />Selected option Text: "+ txt);
<select id="ddlViewBy">
<option value="1">test1</option>
<option value="2">test2</option>
<option value="3" selected="selected">test3</option>
</select>
Note: The values don't change as the dropdown is changed, if you require that functionality then an onClick change is to be implemented.
To go along with the previous answers, this is how I do it as a one-liner. This is for getting the actual text of the selected option. There are good examples for getting the index number already. (And for the text, I just wanted to show this way)
let selText = document.getElementById('elementId').options[document.getElementById('elementId').selectedIndex].text
In some rare instances you may need to use parentheses, but this would be very rare.
let selText = (document.getElementById('elementId')).options[(document.getElementById('elementId')).selectedIndex].text;
I doubt this processes any faster than the two line version. I simply like to consolidate my code as much as possible.
Unfortunately this still fetches the element twice, which is not ideal. A method that only grabs the element once would be more useful, but I have not figured that out yet, in regards to doing this with one line of code.
I have a bit different view of how to achieve this. I'm usually doing this with the following approach (it is an easier way and works with every browser as far as I know):
<select onChange="functionToCall(this.value);" id="ddlViewBy">
<option value="value1">Text one</option>
<option value="value2">Text two</option>
<option value="value3">Text three</option>
<option value="valueN">Text N</option>
</select>
In 2015, in Firefox, the following also works.
e.options.selectedIndex
In more modern browsers, querySelector allows us to retrieve the selected option in one statement, using the :checked pseudo-class. From the selected option, we can gather whatever information we need:
const opt = document.querySelector('#ddlViewBy option:checked');
// opt is now the selected option, so
console.log(opt.value, 'is the selected value');
console.log(opt.text, "is the selected option's text");
<select id="ddlViewBy">
<option value="1">test1</option>
<option value="2" selected="selected">test2</option>
<option value="3">test3</option>
</select>
event.target.value inside the onChange callback did the trick for me.
Most answers here get the value of the "this" select menu onchange by a plain text JavaScript selector.
For example:
document.getElementById("ddlViewBy").value;
This is not a DRY approach.
DRY (three lines of code):
function handleChange(e) {
let innerText = e.target[e.target.options.selectedIndex].innerText;
let value = e.target.value;
/* Do something with these values */
}
Get the first select option:
console.log(e.target[0]); /* Output: <option value="value_hello">Hello innerText</option>*/
With this idea in mind, we dynamically return a "this" select option item (by selectedIndex):
e.target[e.target.options.selectedIndex].innerText;
Demo
let log = document.getElementById('log');
function handleChange(e) {
let innerText = e.target[e.target.options.selectedIndex].innerText;
let value = e.target.value;
log.innerHTML = `<table>
<tr><th>value</th><th>innerText</th></tr>
<tr><td>${value}</td><td>${innerText}</td></tr>
</table>`;
}
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/milligram/1.4.1/milligram.css">
<select id="greet" onchange="handleChange(event)">
<option value="value_hello">Hello innerText</option>
<option value="value_goodbye">Goodbye innerText</option>
<option value="value_seeYou">See you... innerText</option>
</select>
<select id="other_select_menu" onchange="handleChange(event)">
<option value="value_paris">Paris innerText</option>
<option value="value_ny">New York innerText</option>
</select>
<div id="log"></div>
Here is a JavaScript code line:
var x = document.form1.list.value;
Assuming that the dropdown menu named list name="list" and included in a form with name attribute name="form1".
I think you can attach an event listener to the select tag itself e.g:
<script>
document.addEventListener("DOMContentLoaded", (_) => {
document.querySelector("select").addEventListener("change", (e) => {
console.log(e.target.value);
});
});
</script>
In this scenario, you should make sure you have a value attribute for all of your options, and they are not null.
You should be using querySelector to achieve this. This also standardizes the way of getting a value from form elements.
var dropDownValue = document.querySelector('#ddlViewBy').value;
Fiddle: https://jsfiddle.net/3t80pubr/
Try
ddlViewBy.value // value
ddlViewBy.selectedOptions[0].text // label
console.log( ddlViewBy.value );
console.log( ddlViewBy.selectedOptions[0].text );
<select id="ddlViewBy">
<option value="1">Happy</option>
<option value="2">Tree</option>
<option value="3" selected="selected">Friends</option>
</select>
Here's an easy way to do it in an onchange function:
event.target.options[event.target.selectedIndex].dataset.name
<select name="test" id="test" >
<option value="1" full-name="Apple">A</option>
<option value="2" full-name="Ball">B</option>
<option value="3" full-name="Cat" selected>C</option>
</select>
var obj = document.getElementById('test');
obj.options[obj.selectedIndex].value; //3
obj.options[obj.selectedIndex].text; //C
obj.options[obj.selectedIndex].getAttribute('full-name'); //Cat
obj.options[obj.selectedIndex].selected; //true
There is a workaround, using the EasyUI framework with all of its plugins.
You only need to add some EasyUI object that can read from an input as a "bridge" to the drop-down menu.
Example: easyui-searchbox
To the left, the drop-down, to the right, the easyui-searchbox:
...
<input id="ss" class="easyui-searchbox" style="width:300px"
data-options=" searcher:my_function,
prompt:'Enter value',
menu:'#mm'">
<div id="mm" style="width:200px">
<div data-options="name:'1'">test1</div>
<div data-options="name:'2'">test2</div>
</div>
...
...
<script type="text/javascript">
function my_js_function(triggeredByButton = false){
// normal text of the searchbox (what you entered)
var value = $("#ss").searchbox("getValue");
// what you chose from the drop-down menu
var name = $("#ss").searchbox("getName");
...
Mind: the var name is the '1' or '2', that is, the "value of the drop-down", while var value is the value that was entered in the easyui-searchbox instead and not relevant if you only want to know the value of the drop-down.
I checked how EasyUI fetches that #mm name, and I could not find out how to get that name without the help of EasyUI. The jQuery behind getName:
getName:function(jq){
return $.data(jq[0],"searchbox").searchbox.find("input.textbox-value").attr("name");
}
Mind that the return of this function is not the value of the easyui-searchbox, but the name of the #mm drop-down that was used as the menu parameter of the easyui-searchbox. Somehow EasyUI must get that other value, therefore it must be possible.
If you do not want any plugin to be seen, make it as tiny as possible? Or find perhaps a plugin that does not need a form at all in the link above, I just did not take the time.
I have this html:
<select onchange="check_status(this);" name="status[171]">
<option selected="true" value="open" data="04f2cf35e4d7a1c0158459fd0450a605">open</option>
<option value="in_process" data="04f2cf35e4d7a1c0158459fd0450a605">pending</option>
<option value="finished" data="04f2cf35e4d7a1c0158459fd0450a605">finished</option>
<option value="canceled" data="04f2cf35e4d7a1c0158459fd0450a605">canceled</option>
</select>
and js
function check_status(obj){
var uid = obj.getAttribute('data');
alert(uid);
}
but it always alerts null instead of data value
Where is the problem guys? Thanks
The problem is that you get select element and not selected option element as function argument. And it does not have the data attribute. You have to get the option attribute like so:
function check_status(obj) {
var uid = obj.options[obj.selectedIndex].getAttribute('data-uid');
alert(uid);
}
<select onchange="check_status(this);" name="status[171]">
<option selected="true" value="open" data-uid="01f2cf35e4d7a1c0158459fd0450a601">open</option>
<option value="in_process" data-uid="02f2cf35e4d7a1c0158459fd0450a602">pending</option>
<option value="finished" data-uid="03f2cf35e4d7a1c0158459fd0450a603">finished</option>
<option value="canceled" data-uid="04f2cf35e4d7a1c0158459fd0450a604">canceled</option>
</select>
Notice that I changed the attribute name to data-uid for it to be valid according to HTML5 specificaion.
You are trying to get select data attribute, and not option's.
Also, I can see that all you data attributes are identical. Then you can move it from option to select itself: <select onchange="check_status(this);" name="status[171]" data="04f2cf35e4d7a1c0158459fd0450a605" > and use code snipped from your question unmodified.
function check_status(obj) {
var uid = obj.options[obj.selectedIndex].getAttribute('data');
alert(uid)
}
<select onchange="check_status(this);" name="status[171]">
<option selected="true" value="open" data="open04f2cf35e4d7a1c0158459fd0450a605">open</option>
<option value="in_process" data="pending104f2cf35e4d7a1c0158459fd0450a605">pending</option>
<option value="finished" data="finished04f2cf35e4d7a1c0158459fd0450a605">finished</option>
<option value="canceled" data="canceled04f2cf35e4d7a1c0158459fd0450a605">canceled</option>
</select>
You define custom attributes using the "data" attribute. In your code, there is not custome attribute which I'm sure you wanted it to be an ID. The exact format is "data-*", where "*" is replaced with the desired custom attribute name, then set to the desired string value. So in your code, it should ideally be:
<select onchange="check_status(this);" name="status[171]">
<option selected="true" value="open" data-id="open04f2cf35e4d7a1c0158459fd0450a605">open</option>
<option value="in_process" data-id="pending104f2cf35e4d7a1c0158459fd0450a605">pending</option>
<option value="finished" data-id="finished04f2cf35e4d7a1c0158459fd0450a605">finished</option>
<option value="canceled" data-id="canceled04f2cf35e4d7a1c0158459fd0450a605">canceled</option>
</select>
assuming you want the custom attribute to be "id".
There are two ways you can retrieve the value of "data" attributes using pure JavaScript: in addition to the good old fashion get/setAttribute(), you can also access using the "dataset" property of the element
Using DOM's getAttribute() property
function check_status(obj) {
var myoption = obj.options[obj.selectedIndex];
var uid = myoption.getAttribute('data');
alert(uid);
// setting and removing the data-id attribute
myoption.setAttribute("data-id", "foo") //changes "data-id" to "foo"
myoption.removeAttribute("data-id") //removes "data-id" attribute entirely
}
Using JavaScript's dataset property
function check_status(obj) {
var myoption = obj.options[obj.selectedIndex];
var uid = myoption.dataset.id;
alert(uid);
var statusId = myoption.dataset["id"]
alert(statusId);
}
function check_status(obj){
var uid = obj.options[obj.selectedIndex].getAttribute('data');
alert(uid);
}
This has probably been answered, but I am unable to find the answered question anywhere...
Assuming we have the following HTML...
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Dropdown Test</title>
</head>
<body>
<select name="myDropDownListName" id="myDropDownListID" class="dropdown">
<option selected="selected" value="0">Please select a value...</option>
<option value="1">My Custom Value 1</option>
<option value="2">My Custom Value 2</option>
<option value="3">My Custom Value 3</option>
</select>
</body>
</html>
What would the JQuery command look like to set 'My Custom value 2' to be the currently selected option in the dropdown list box, assuming I do not know the index 'value' value, and can only identify the item by the text 'My Custom Value 2'?
You can use jquery .filter():
$('#myDropDownListID option').filter(function() {
//you can use this.innerText too
return $(this).text() === 'My Custom Value 2';
}).prop('selected', true);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select name="myDropDownListName" id="myDropDownListID" class="dropdown">
<option selected="selected" value="0">Please select a value...</option>
<option value="1">My Custom Value 1</option>
<option value="2">My Custom Value 2</option>
<option value="3">My Custom Value 3</option>
</select>
Simply like this :
$('select').val($("select option:contains('My custom Value 2')").val());
Another way... use the contains selector to search for a DOM elem by its content.
$('select>option:contains("My Custom Value 2")').prop('selected', true);
People like to say to use .val(), but as you noticed, it doesn't like to set by text, but by using the index, instead. So you should do a find to get that, then set by it. But even that is only part of the story. You should first deselect all other options, and set the attribute of the option you want as selected using the index that you find.
Btw, I hate the $('#myDropDownListID') syntax because it is useless in SharePoint because it auto-generates GUIDs and puts them after the IDs, forcing you to have to grab it with $('[id*=myDropDownListID]'), with the * indicating that it contains that value, so that is how I will set this up, except I'll leave out the * because it's unnecessary in this case. But this syntax is also very useful if you want to use $ instead of * to say it starts with that value, and you can use title or name instead of id, so it is incredibly versatile, and I wish more people used it.
$(document).ready(function() {
var yourText = "My Custom Value 2";
// Remove all 'selected' attributes from all options
$('select[id="myDropDownListID"] option').removeAttr('selected');
// Get the index for the value you want to set
var idx = $('select[id="myDropDownListID"] option').filter(function() {
return $(this).html() == yourText;
}).val();
// Set the dropdown value by index and set it as selected by text
var dropdownBox = $('select[id="myDropDownListID"]');
dropdownBox.val(idx);
dropdownBox.find('option[value="' + yourValue + '"]').attr('selected','selected'); // note that .val() doesn't do this
dropdownBox.click(); // may be useful and necessary for certain engines to cache the value appropriately
console.log(dropdownBox.html()); // should show you that the selected option is My Custom Value 2
console.log(dropdownBox.val()); // should give you the index 2
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.2.3/jquery.min.js"></script>
<select id="myDropDownListID">
<option value="1">My Custom Value 1</option>
<option value="2">My Custom Value 2</option>
<option value="3">My Custom Value 3</option>
</select>
ddlListItems is ID of ListBox
if ($('#ddlListItems option:selected').text() == 'My Custom Value 2') {
var itemsByValue = $('#ddlListItems option:selected').text();
}