JSLint (with the onevar flag turned on) is flagging some javascript code that I have with the following:

Problem at line 5 character 15: Too many var statements.

I am happy to fix these errors, but I'd like to know, am I doing it for performance or because it is just a bad practice and has a greater potential to introduce bugs in my javascript code. What is the reason behind the onevar flag?

I did look at the JSLint docs for the var keyword but it doesn't specifically talk about why multiple var statements in the same function are bad.

Here is an attempt at an example. Explain how the code will benefit from only having 1 var statement:

function Test(arg) {

   var x = arg + 1,

       y = cache.GetItem('xyz');

   if (y !== null) {

      // This is what would cause the warning in JSLint

      var request = ajaxPost(/* Parameters here */);



   }

}