Returning a value

The methods so far did their work and gave nothing back: they were void. A method can instead return a value to the code that called it. The value's type goes where void was, and a return statement says what to give back:

public class Main {
    public static void main(String[] args) {
        int weeks = 3;
        int days = weeks * daysInWeek();
        System.out.println(weeks + " weeks is " + days + " days");
        System.out.println(daysInWeek());
    }

    public static int daysInWeek() {
        return 7;
    }
}

3 weeks is 21 days
7

• public static int daysInWeek() says the method returns an int.
• return 7; ends the method and hands 7 back to the call.
• The call daysInWeek() then stands for that value, anywhere a value can go: in a calculation, in a print line, or stored in a variable (int d = daysInWeek();).

A call whose value isn't used, like daysInWeek(); on a line of its own, runs the method, and the value is simply lost.

return ends the method

Nothing after a return runs, and Java refuses code that could never run:

public class Main {
    public static void main(String[] args) {
        System.out.println(daysInWeek());
    }

    public static int daysInWeek() {
        return 7;
        System.out.println("Counted the days");
    }
}

Main.java:8: error: unreachable statement
        System.out.println("Counted the days");
        ^
1 error

A void method can use a plain return; to stop early.