You have learned how to print something using JavaScript on console in the previous chapter. Now, let's see the fundamentals behind JavaScript syntax, variables, arithmetic operators, and comments.

In the computer world, there is nothing but data. You can read, modify, and create new data; however, anything that isn't data simply does not exist. In JavaScript, we need to handle data to develop a website.

To understand the basic syntax of JavaScript, first of all you need to know that JavaScript is case sensitive. You cannot interchange lower case and upper case letters in JavaScript. Therefore, when dealing with the JavaScript syntax, you need to remember that writing the code is not the only important task, you must also watch the syntax whether it's written correctly.

Let me show you an example. In the previous chapter, you have successfully printed Hello World on your browser using the document.write(); syntax.

What would happen if you wrote Document...