Comments

Comments are pieces of text in our code that Java ignores. We use them to explain what the code does, or to disable parts of the code without deleting them

In Java, a single-line comment starts with //

public class Main {
    public static void main(String[] args) {
        // this is a comment
        int a = 1 + 2 + 3;
        System.out.println(a); // display variable a
    }
}

The lines after // are completely ignored by Java. The program runs as if they weren’t there

Comments are also great for disabling code temporarily

public class Main {
    public static void main(String[] args) {
        int a = 1 + 2 + 3;
        // System.out.println(a);
    }
}

Now the program prints nothing, because we commented out the println. Very useful when debugging: instead of deleting code and rewriting it later, we just comment it out

For longer comments that span multiple lines, Java also supports /* ... */

/*
This is a
multi-line
comment
*/

However, in practice, most Java code uses // even for several lines in a row

// this is how we will write
// our comments
// to give hints
// and to explain things

There’s also a special kind, /** ... */, used to document classes and methods. We’ll meet it later in your Java journey. For now, // is all you need

Mission: Classified Cargo

The ship’s manifest is displayed on the main screen, but one line contains classified cargo that must stay hidden from the crew.

Comment out one line so that only the ship’s name, mission name, and maximum power are printed. Do not delete anything, just use // to hide the secret.

Input (already set at the top of your code; change the values to test):

• shipName: the ship’s name
• missionName: the current mission
• secretCargo: classified item (this must NOT appear in the output)
• maxPower: engine power level

Example

With the default values, your program should print

Voyager
Deep Space Exploration
9001