We have been discussing variables, constants and data types. I wanted to take a moment to speak about initialization of data. Each language might do this a touch differently, but they all have a way to initialize data.
So what is initialization? It simply means putting content into your variable or constant. In JavaScript, it is done like this…
[code lang=”js”]
var testVar = "I am initialized!";
[/code]
If you do not initialize your variables, you could end up receiving undefined errors within your program. So if you use a variable that you do not initialize, take care to test it prior to using it.
JavaScript constants always need to be initialized when they are created.
So what does an uninitialized variable look like?
[code lang=”js”]
var testVar;
[/code]
That’s it.
A good practice would be to initialize all of your variables at least with a default value. For example, say I am writing a program where I am collecting someone’s age. I could initialize it as follows…
[code lang=”js”]
var myAge = 0;
[/code]
I start it off with a zero (0) because I know that know one is going to say they are zero years old, unless we have some sort of prebirth genius that can use computers from the womb and that is just weird. So, now I can test the variable in my code. I can check to see if the value of it is zero (0). If it is, then the end user has not told me how old they are…maybe they are ashamed?
Happy Coding!
Clay
