jQuery .val() vs .attr("value")

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.

在我构建的另一个页面上，$obj.attr("value")和$obj.val()都返回在表单字段中输入的文本。

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?

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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.

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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.

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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.

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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.

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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.

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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');

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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.

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jQuery('.changer').change(function () {
var addressdata = jQuery('option:selected', this).attr('address');
jQuery("#showadd").text(addressdata);
});
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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()

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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>

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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>
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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.

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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.

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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;

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