I had thought these two were the same, but they appear to not be. I've generally been using $obj.attr("value") to work with form fields, but on the page I'm currently building, $obj.attr("value") does not return the text I enter in my field. However, $obj.val() does.
On a different page I've built, both $obj.attr("value") and $obj.val() return the text entered in the form field.
What could account for $obj.attr("value") working as expected in one case but not in another?
What is the proper way to set and retrieve a form field's value using jQuery?
There is a big difference between an objects properties and an objects attributes
See this questions (and its answers) for some of the differences: .prop() vs .attr()
The gist is that .attr(...) is only getting the objects value at the start (when the html is created). val() is getting the object's property value which can change many times.
Since jQuery 1.6, attr() will return the original value of an attribute (the one in the markup itself). You need to use prop() to get the current value:
var currentValue = $obj.prop("value");
However, using val() is not always the same. For instance, the value of <select> elements is actually the value of their selected option. val() takes that into account, but prop() does not. For this reason, val() is preferred.
PS: This is not an answer but just a supplement to the above answers.
Just for the future reference, I have included a good example that might help us to clear our doubt:
Try the following. In this example I shall create a file selector which can be used to select a file and then I shall try to retrieve the name of the file that I selected:
The HTML code is below:
<html>
<body>
<form action="#" method="post">
<input id ="myfile" type="file"/>
</form>
<script type="text/javascript" src="jquery.js"> </script>
<script type="text/javascript" src="code.js"> </script>
</body>
</html>
The code.js file contains the following jQuery code. Try to use both
of the jQuery code snippets one by one and see the output.
jQuery code with attr('value'):
$('#myfile').change(function(){
alert($(this).attr('value'));
$('#mybutton').removeAttr('disabled');
});
jQuery code with val():
$('#myfile').change(function(){
alert($(this).val());
$('#mybutton').removeAttr('disabled');
});
Output:
The output of jQuery code with attr('value') will be 'undefined'.
The output of jQuery code with val() will the file name that you selected.
Explanation:
Now you may understand easily what the top answers wanted to convey. The output of jQuery code with attr('value') will be 'undefined' because initially there was no file selected so the value is undefined. It is better to use val() because it gets the current value.
In order to see why the undefined value is returned try this code in your HTML and you'll see that now the attr.('value') returns 'test' always, because the value is 'test' and previously it was undefined.
<input id ="myfile" type="file" value='test'/>
I hope it was useful to you.
Let's learn from an example.
Let there be a text input field with default value = "Enter your name"
var inp = $("input").attr("value");
var inp = $("input").val();
Both will return "Enter your name"
But suppose you change the default text to "Jose" in your browser.
var inp = $("input").attr("value");
will still give the default text i.e. "Enter your name".
var inp = $("input").val();
But .val() will return "Jose", i.e. the current value.
Hope it helps.
The proper way to set and get the value of a form field is using .val() method.
$('#field').val('test'); // Set
var value = $('#field').val(); // Get
With jQuery 1.6 there is a new method called .prop().
As of jQuery 1.6, the .attr() method returns undefined for attributes
that have not been set. In addition, .attr() should not be used on
plain objects, arrays, the window, or the document. To retrieve and
change DOM properties, use the .prop() method.
In order to get the value of any input field, you should always use $element.val() because jQuery handles to retrieve the correct value based on the browser of the element type.
jQuery('.changer').change(function () {
var addressdata = jQuery('option:selected', this).attr('address');
jQuery("#showadd").text(addressdata);
});
jQuery(".morepost").live("click", function() {
var loadID = jQuery(this).attr('id'); //get the id
alert(loadID);
});
you can also get the value of id using .attr()
this example may be useful:
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js"></script>
</head>
<body>
<input id="test" type="text" />
<button onclick="testF()" >click</button>
<script>
function testF(){
alert($('#test').attr('value'));
alert( $('#test').prop('value'));
alert($('#test').val());
}
</script>
</body>
</html>
in above example, everything works perfectly. but if you change the version of jquery to 1.9.1 or newer in script tag you will see "undefined" in the first alert.
attr('value') doesn't work with jquery version 1.9.1 or newer.
Example more... attr() is various, val() is just one! Prop is boolean are different.
//EXAMPLE 1 - RESULT
$('div').append($('input.idone').attr('value')).append('<br>');
$('div').append($('input[name=nametwo]').attr('family')).append('<br>');
$('div').append($('input#idtwo').attr('name')).append('<br>');
$('div').append($('input[name=nameone]').attr('value'));
$('div').append('<hr>'); //EXAMPLE 2
$('div').append($('input.idone').val()).append('<br>');
$('div').append('<hr>'); //EXAMPLE 3 - MODIFY VAL
$('div').append($('input.idone').val('idonenew')).append('<br>');
$('input.idone').attr('type','initial');
$('div').append('<hr>'); //EXAMPLE 3 - MODIFY VALUE
$('div').append($('input[name=nametwo]').attr('value', 'new-jquery-pro')).append('<br>');
$('input#idtwo').attr('type','initial');
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<input type="hidden" class="idone" name="nameone" value="one-test" family="family-number-one">
<input type="hidden" id="idtwo" name="nametwo" value="two-test" family="family-number-two">
<br>
<div></div>
jquery - Get the value in an input text box
<script type="text/javascript">
jQuery(document).ready(function(){
var classValues = jQuery(".cart tr").find("td.product-name").text();
classValues = classValues.replace(/[_\W]+/g, " ")
jQuery('input[name=your-p-name]').val(classValues);
//alert(classValues);
});
</script>
If you get the same value for both property and attribute, but still sees it different on the HTML try this to get the HTML one:
$('#inputID').context.defaultValue;
In attr('value') you're specifically saying you're looking for the value of an attribute named vaule. It is preferable to use val() as this is jQuery's out of the box feature for extracting the value out of form elements.
I have always used .val() and to be honest I didnt even know you could get the value using .attr("value"). I set the value of a form field using .val() as well ex. $('#myfield').val('New Value');
I have some code for Javascript using jQuery, and I've been wondering how to fix an element of it.
var dataGiven = +$("span.cost-in-usd:first-child").text();
However, the span tag is:
<span class="cost-in-usd" data-se="product-usd-value">42</span>
Is there a way of modifying my code in order for it to recognise data-se?
Yes, use data.
var datase = $('.cost-in-usd').data('se');
Some links;
http://api.jquery.com/jquery.data/
Here's a jsfiddle
The following will return the value of attribute
$('.cost-in-usd').attr('data-se');
I have a string like follows in javascript
var str='<img class="avatar avatar-small 012345" src="/img/staff_avatar_profile.jpg" /> olah blah';
I need to get every time the number like for this example 012345. Which will be ofcourse be different in different scenario and I also need to get the text olah blah which will be also different in different scenario.
I have the above string in a variable. ;)
How can i perform this in a efficient manner in java-script
The best way to parse HTML in a browser is to let the browser do it for you:
var div = document.createElement('div');
div.innerHTML = str;
var numbers = div.getElementsByTagName('img')[0].className.match(/ (\d+)/)[1];
Here's the fiddle: http://jsfiddle.net/CGuLC/1/
You could use jQuery if it works there to get an only numeric class name. Take a look at jQuery - selectors on a html string to get a clue.
Use the data attribute instead of class.
<img class="avatar avatar-small" data-id="012345" src="/img/staff_avatar_profile.jpg" />
Then use jQuery to get the data attribute.
jQuery('.avatar').data('id');
Sources:
http://html5doctor.com/html5-custom-data-attributes/
http://api.jquery.com/data/
If you need to store data for an element, one good way to achieve that is to use the data-key attribute with jQuery:
$('.avatar').data('number', '012345'); // set value
var number = $('.avatar').data('number'); // get value
The rendered markup will look like this:
<img class="avatar avatar-small" data-number="012345" src="/img/staff_avatar_profile.jpg" />
Im sending over some json data and assigning to a hidden field using:
#Html.Hidden("hidden-places", #Model.Places)
inside my javascript i am doing the following to retrieve the data:
var places = $('#hidden-places').val();
however it just comes back as undefined.
i am using this for google maps...
i tried something like:
$(document).ready(function () {
places = $('#hidden-places').val();
// Onload handler to fire off the app.
google.maps.event.addDomListener(window, 'load', initialize);
});
but no luck.
You need to use an ID selector:
places = $('#hidden-places').val();
Note that #.
With this:
$('hidden-places').val();
...you're looking for the value of a <hidden-places> element. Probably not what you mean. You likely want the value of a field with the ID hidden-places:
$('#hidden-places').val();
I had multiple elements with the same id on the page causing the problem
"hidden-places" will be the ID of the field and what your jQuery is looking for is going to be an HTML element called hidden-places.
You should use
$('#hidden-places').val()
did you check if you set a prefix in your viewdata?
how is the element in DOM? checked the value and id?
maybe your element is like
<input id="prefix_hidden-places" name="prefix.hidden-places" type="hidden" value="10" />
I have some HTML that is stored as an attribute on a tag. I can access it in jQuery using
$("input[id$='_myField_hiddenSpanData']").attr("value")
This looks like this:
"<span id='spantest\user' tabindex='-1' contentEditable='false' class='ms-entity-resolved' title='test\user'><div style='display:none;' id='divEntityData' key='test\user' displaytext='Test User' isresolved='True' description='test\user'><div data=''></div></div><span id='content' tabindex='-1' contenteditable onMouseDown='onMouseDownRw();' onContextMenu='onContextMenuSpnRw();' >Test User</span></span>"
I would need the value of the key attribute (test\user). Can I somehow tell jQuery to parse a block of HTML and apply selectors to it? I found I can wrap it into a new jQuery object by wrapping it into another $(): $($("input[id$='_myField_hiddenSpanData']").attr("value")) but I still did not manage to apply a selector on it.
Any hints? And no, sadly I do not control the markup that generates the hidden field.
Wrap your crappy markup with a jQuery object, and then use the find function to apply a selector to it...
var crappyHtml = $("input[id$='_myField_hiddenSpanData']").attr("value");
var key = $(crappyHtml).find("div[key]").attr("key");
alert(key);
Try this:
var html = $("input[id$='_myField_hiddenSpanData']").attr("value");
var user = $(html).find("#divEntityData").attr("key");
alert("user=" + user);
You should be able to pass it as a context. Does this work?:
$('#divEntityData', $($("input[id$='_myField_hiddenSpanData']").attr("value"))).attr('key');