Prevention of runtime errors
Avoiding memory leaks
Faster to the end user
Java Script is written for the client end, then it would require the web’s server support for execution. There has to be compilation at the client side that would provide it with certain speed advantages. Since the script is executed on the user’s computer the results are arrived instantly. An example is that you may validate it any user output before you send out a request to the user. The load on the server is less.
Modern form of scripting language
Being an old language it has been sunk in by a variety of advanced level languages. There are numerous scripting languages on offer that enables you to achieve the same or an advanced degree of functionality with the same level of effort.