Commenting Code
Writing code is an exciting process of instructing the computer to complete fantastic tasks.
Code is also read by people, and we want our intentions to be clear to humans just like we want our instructions to be clear to the computer.
Fortunately, we’re not limited to writing syntax that performs a task. We can also write comments, notes to human readers of our code. These comments are not executed, so there’s no need for valid syntax within a comment.
When comments are short we use the single-line syntax: //.
// calculate customer satisfaction rating
When comments are long we use the multi-line syntax: /* and */.
/*
We chose to store information across multiple databases to
minimize the possibility of data loss. We'll need to be careful
to make sure it does not go out of sync!
*/
Here’s how a comment would look in a complete program:
public class CommentExample {
// I'm a comment inside the class
public static void main(String[] args) {
// I'm a comment inside a method
System.out.println("This program has comments!");
}
}
Comments are different from printing to the screen, when we use System.out.println(). These comments won’t show up in our terminal, they’re only for people who read our code in the text editor.
- Sample code segment with commenting
public class Timeline {
public static void main(String[] args) {
System.out.println("Hello Java!");
System.out.println("You were born in 1995");
// Sun Microsystems announced the release of Java in 1995
System.out.println("You were created by James Gosling");
/*
James Gosling is a Canadian engineer who
created Java while working at Sun Microsystems.
His favorite number is the square root of 2!
*/
System.out.println("You are a fun language!");
}
}
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