In these modern days mobile devices are really very common. So every programmer should be aware of their applications compatibility with mobile devices. For that the applications must have the functionality to Detect Mobile Devices. Using JavaScript or jQuery it is really very easy to Detect Mobile Devices.

How to Detect Mobile Devices with jQuery or JavaScript

There are many ways to detect Mobile Devices. In this lesson I will share some tricks on How to Detect Mobile Devices with Javascript or jQuery. So lets get started.

1. Using a JavaScript Function to Detect Mobile Devices

This example shows a function which will return if your device is Mobile or not.

var isMobile = {
    Android: function() {
        return navigator.userAgent.match(/Android/i);
    },
    BlackBerry: function() {
        return navigator.userAgent.match(/BlackBerry/i);
    },
    iOS: function() {
        return navigator.userAgent.match(/iPhone|iPad|iPod/i);
    },
    Opera: function() {
        return navigator.userAgent.match(/Opera Mini/i);
    },
    Windows: function() {
        return navigator.userAgent.match(/IEMobile/i);
    },
    any: function() {
        return (isMobile.Android() || isMobile.BlackBerry() ||
            isMobile.iOS() || isMobile.Opera() || isMobile.Windows());
    }
};

Now you can check if its a Mobile Device by using this function:

if(isMobile.any()) {
   alert("This is a Mobile Device");
}

If this is a Mobile Device then an alertbox will popup.

2. Another JavaScript trick to Detect Mobile Devices

This simple code will check if the current device is a mobile and you can put your tasks inside the if statement when it detects a Mobile Device.

if( /Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|
    Opera Mini/i.test(navigator.userAgent) )
{
    // tasks to do if it is a Mobile Device
    alert("Mobile Detected");
}

3. Using jQuery or any other popular language

Detect Mobile Browser has a great collection of scripts to Detect Mobile Devices. You can get Mobile Device detection scripts for Apache, ASP, ASP.NET, ColdFusion, C#, IIS, JSP, JavaScript, jQuery, Lasso, nginx, node.js, PHP, Perl, Python, Rails etc. The script list is pretty much big so don’t hesitate to explore this with your favorite language script.

There is also a JavaScript Library named isMobile. It is really fast and very easy to use. So you can give it a try. 

Hope now you know how to Detect Mobile Devices.

[출처] http://jstricks.com/detect-mobile-devices-javascript-jquery/