public class Recursion {

    /*
     * 用递归判断一个数是不是质数？
     */
    static int numberO;
    static boolean flag = true;

    public static void main(String[] args) {
        if (isPrimeNumber(-1) > 0)
            System.out.println(numberO + " 是质数");
        else
            System.out.println(numberO + " 是非质数");
    }

    private static int isPrimeNumber(int number) {
        if (flag) {
            number = numberO = Math.abs(number);
            flag = false;
            if (numberO < 2)
                return -1;
        }
        if (number > 2 && (numberO % (--number)) == 0)
            return -1;
        else
            return number > 2 ? isPrimeNumber(number) : 1;
    }
}

------解决方案--------------------

更加完善的递归调用了


Java code

public class Recursion {
    /*
     * 用递归判断一个数是不是质数？
     */
    static int numberO;
    static boolean flag = true;

    public static void main(String[] args) {
        for (int i = 0; i < 100; i++) {
            if (isPrimeNumber(i) > 0)
                System.out.println(numberO + " 是质数");
            else
                System.out.println(numberO + " 是非质数");
            flag = true;
        }
    }

    private static int isPrimeNumber(int number) {
        if (flag) {
            number = numberO = Math.abs(number);
            flag = false;
            if (numberO < 2)
                return -1;
        }
        if (number > 2 && (numberO % (--number)) == 0)
            return -1;
        else
            return number > 2 ? isPrimeNumber(number) : 1;
    }
}