JAVA如何简化迭代

Question

How can i simplify this code using loops or some other kind of methods? For example i need to iterate not just 4 times but n times? For example now i am doing 4 calculations and 4 system.out.prints, how can i change or what i can use that those 4 calculations would be looped automatically, because for example if i need to do like 100 or more calculations not just 4.

 public class A {
        public static void main(String[] args) {
            int A = 22;
            int APRme = 12;

            int I = APRme * A % 10;
            int AR1 = I * A % 10;
            int AR2 = AR1 * A % 10;
            int AR3 = AR2 * A % 10;

            System.out.println(I);
            System.out.println(AR1);
            System.out.println(AR2);
            System.out.println(AR3);
        }
    }

Answer 1

You can create a loop which would perform the calculations a given number (n) of times. For example, your current code does it four times:

public class A {
    public static void main(String[] args) {
        int A = 22;
        int APRme = 12;
        int result = APRme;
        int n = 4; // How many times would you like to do the calculations

        for (int i = 1; i <= n; i++) {
            result = result * A % 10;

            System.out.println(result);
        }
    }
}

Answer 2

In this particular example I would leave the code exactly as it is right now. The nice thing about this code is that it is short and readable, and when you step through it using a debugger, you can inspect each intermediate result. In case of a bug this will show you exactly at which point the error happened.

If you still want to write it as a loop, it is written:

int intermediate = start;
for (int i = 0; i < 4; i++) {
    intermediate = intermediate * A % 10;
    System.out.println(intermediate);
}

The line that starts with for looks so complicated for historic reasons. It basically just says "do the following 4 times".