Chapter 3. DOM Scripting and AJAX

When it comes to Document Object Model (DOM) manipulation and AJAX, the first instinct could be to use jQuery or Zepta. But doesn't it bother you that you load a weighty third-party library for common tasks, when a browser provides everything that you need? Some people pulled in jQuery for cross-browser compatibility. Well, the library is known to fix the broken DOM API. This was really helpful when we supported browsers as old as IE7. However, today we hardly need to care about legacy browsers when their usage share is less than 0.1 percent (http://www.w3schools.com/browsers/browsers_explorer.asp). Modern browsers are quite consistent in the support of Web API. By and large, cross-browser compatibility is not an issue anymore.

The second and the most common excuse is that the library simplifies the amount of code you have to write to query and manipulate the DOM. It really simplifies the code to some degree, but the drawback is that nowadays...