Professional JavaScript for Web Developers
Chapter One
What Is JavaScript?
When JavaScript first appeared in 1995, its main purpose was to handle some of the input
validation that had previously been left to server-side languages such as Perl. Prior to that time, a
round-trip to the server was needed to determine if a required field had been left blank or an
entered value was invalid. Netscape Navigator sought to change that with the introduction of
JavaScript. The capability to handle some basic validation on the client was an exciting new feature
at a time when use of telephone modems was widespread. The associated slow speeds turned
every trip to the server into an exercise in patience.
Since that time, JavaScript has grown into an important feature of every major web browser on the
market. No longer bound to simple data validation, JavaScript now interacts with nearly all
aspects of the browser window and its contents. JavaScript is recognized as a full programming
language, capable of complex calculations and interactions, including ... read full excerpt from: Professional JavaScript for Web Developers ebook
