Many JavaScripts deal with variables. This is where you take a word or letter and assign a value to it. The value can be either numbers or words. To think of it in physical terms, imagine a box with a label stuck on it and there is a piece of paper with a name or number written on it inside the box. The labeled box is a variable, and the name or number on the paper is the value.

var Z = X + Y If X=1 and Y=2 then Z=3.

Look horribly familiar? It's the stuff you learn in school and think to yourself "When will I EVER need to know algebra in real life ?". Well... here it is.

You can use strings (regular text) instead of numbers in these equations too. Or a number and a string.

"This is " + "HTMlite." "HTMlite " + 99

This is HTMlite. HTMlite 99

Other than the usual assignment operators + - / * = you can use JavaScript to compare two or more variables with each other. That is, it takes two values and compares them to each other. Here is a list of the different types of comparisons there are :

X == Y X != Y X > Y X >= Y X < Y X <= Y X && Y X || Y !X

True if X and Y are equal. True if X and Y are not equal. True if X is greater than Y. True if X is greater than or equal to Y. True if X is less than Y. True if X is less than or equal to Y. True if X and Y are true values. True if X or Y have a true value. True if X has a false value.

As stated before, part of having a numeric value in variables lets you use regular math expressions on them like so...

X += Y X -= Y X *= Y X /= Y X %= Y

X = X + Y X = X - Y X = X * Y X = X / Y X = X % Y