Learning some javascript

As part of my work I need to be a “Jack of all trades” meaning I not only need to be able to do SQL Server DBA and development tasks, but I also need to be capable of doing .NET and VFP development.  Yes, I did say VFP (Visual FoxPro for those who are too young to know what it is). 

The major project in which I am involved is using SQL Server and ASP.NET (C#) MVC.  Fortunately I had downloaded Scott Guthrie’s NerdDinner tutorial when it first came out and have just finished going through it.  In the tutorial I came across some code like this:

if (item.Description !== undefined) {
            description = item.Description;
        }

Well, I had never seen the !== operator before and assumed that it was a typo and was supposed to be:

if (item.Description != undefined) {
            description = item.Description;
        }

since I know that == the equality comparison operator and != is the inequality comparison operator.  Well, then I found the same operator later in the code, so I thought, “Hmmm, maybe this isn’t a typo, but a real operator?”, so off to www.google-vs-bing.com to see what I could find.  Well, I didn’t find anything helpful on page 1 of either search engine’s results.  Next a quick question on Twitter.  Ahhh, several replies that, “Yes !== and === are operators and they compare type AND value”.  Having always programmed in strongly typed languages this is new and interesting to me.  So basically in javascript 1 == “1” is true, but 1 === “1” is false.

I still would rather be in SQL, but at least now I am starting to understand more about javascript.