Comments

 

Java, like most programming languages, can include comments. All right, and comments are just basically text inside of your source code that the compiler doesn't see. Right, and there are really kind of just two general uses for comments. One is that it allows you to add human readable notes to your source code, right, it allows you to type things in the source code so that when you look at it later, or someone else looks at it, it's just leaving notes to understand what you were doing there. It's also useful for hiding source cool without deleting it. Maybe you're testing things out, so you want to just kind of take some things away and type some new stuff, or if there's something you don't want to anymore, but you think you want to do it again in the future, so comments allow you to take that stuff out so the content is in your source code, but the compiler doesn't compile it. There are three types of comments in Java. One, which is called line comments, and if you basically just put a double slash, basically the compiler ignores everything until the end of the line, and when I said by the end of the line. it's until you hit the Enter Key, the new line character. It's not like other statements where it relies on the semicolon, right. So, the compiler just skips everything until the next new line. Then what are called block comments where you use a slash star to begin the comment and a star slash to end it. So, the compiler skips everything between those notations. They can be happened in the middle of a line or they can span multiple lines. And the last kind is a special kind of comment called a Javadoc comment, which starts out slash star and then ends star slash. There's a utility called Javadoc that allows you to generate documentation using this special comment format. It allows you basically to write your code documentation right inside of your source code, and then when you run the JavaDoc utility, if you follow the appropriate structure in your comments, that utility will generate documentation right from the source code. The details of Javadoc are outside the scope of this course, but I've got that you URL up there on the screen for you, if you want to dig into Javadoc and learn more about it.