attr() v/s prop() in jQuery – Know the difference and when to use which

This post contains information about Attr() and Prop() method available in jQuery. Most of the developers are confused between Attr() and Prop() method with respective to when to use which and most of the time they use it without knowing the basic difference so I decided to have some post on it.

Let’s start step by step.

What is Attribute?

Attribute in html provides some additional information about that element. All attributes are always specified in the start tag and comes in name/value pair.

<p title=”About us”>This is some information about us….</p>

If you look at above example “title” is the attribute of “p” element. You can provide custom attributes too.

What is Property?

Now let’s understand what property in HTML is. Property is named characteristic of an element in the internal model of an HTML document i.e. DOM.

<input type="text" value="abc" id=”txtInfo”>

In above example, if you wrote a javascript code like txtInfo.value will return the value of textbox i.e. “abc”.

Difference between Attribute and Property in HTML.

Now let’s discuss the difference between Attribute and Property. As said above attributes are written in start tag of an element and properties are represented in DOM.

<input type=”text”  id=”txtInfo” value=”Type Here:”/>

Above mark up will render a textbox with a value “Type here:” within it.

And now if you have typed “abc” in it.

When to use Attr() and Prop() in jQuery

I hope till now you are already cleared about the basic difference between attribute and property and same concept gets applied with Attr() and Prop().

Attr() returns the initial value of some attribute of an element

Prop() returns the current and latest(if changed) value of the property of an element.

Confusion between these two had been started since jQuery introduced their version 1.6 with where they have changed the behavior of attr() method which previously considering properties too while returning the value of attribute which is creating inconsistency in the behavior. Again in version 1.6.1 they have roll backed the behavior of attr() to its old behavior(not exactly same though).

So as conclusion when you want to change the values and want to write some logic on the basis of current values of property such as “checked” property of “checkbox” prefer to use prop() and of initial values are in consideration prefer to use attr().

You can check below live fiddle in which I have checkboxes and I have attempted to toggle its check with prop() and attr() and if you check by clicking on the buttons. “Toggle state(attr)” toggles state for once and then it doesn’t work on the other hand prop() always toggle the state.

I hope this post has benefited you to clear the difference between attr() and prop(). Do share your comments and share this with your friends. Thanks.