Statement Structure and Whitespace

 Java programs are made up of statements. Now, a lot of different things can go on in a statement, and we'll talk about those things throughout this course, but fundamentally, programs are made with statements. Now each statement ends with a semicolon. Java is a language where the newline and the Enter key doesn't really create a new statement. It relies instead on the semicolon. If you're going from any of the C‑based languages, that's something you're very familiar with. Other languages like Visual Basic use the end of line to mark a statement. In Java, it's the semicolon. And the parts of a statement can be separated by zero or more whitespaces, and a whitespace could be many different things. It can be the space character, it can be a tab. And because statements don't end with newline, even the newline itself is just a whitespace in Java. Java's a language that gives us a lot of flexibility with whitespaces, so remember we said that the parts could be separated by zero or more whitespaces, so it allows us to format things in a way that works well for us. So I can have a statement like this where all the parts are pushed all together with no whitespaces between them, but then I can have this same statement where I just put a space after the printing, a space after the parenthesis, a space before the other parenthesis. It'll do the exact same thing. I can put multiple spaces in there, and that still does the exact same thing. Now remember that because the newline is considered a whitespace, I can even format it like this. This is kind of a crazy way to format it, and I wouldn't suggest you do this, but it's all just whitespace. So, after that printing, we've got a newline, followed by a bunch of the space characters. That's fine. Right after that parenthesis, we've got a newline again. After Hello World, we've got a newline, another newline, then a whole bunch of whitespaces or a whole bunch of space characters. And so, it just shows us that the whitespace allows us to indent, format, put line breaks in a way that works well for us. The whitespaces are just separators, and it's that semicolon that marks the end of a statement.