package cuteSnow;

public class HelloWorld {

    // 遍历数组里面的每个数字

    public static void print(int[] array){

        String tip = "数组中每个元素分别为：";

        for(int i = 0; i<array.length; i++) {

           int temNum = array[i];

           tip = tip + temNum +" ";

        }

        System.out.print(tip);

    }

    // 判断给定数据是否为6的倍数

    public static void sixMultiple(int[] array) {

        String tip = "6的倍数有：";

        for(int i = 0; i<array.length; i++) {

            int temNum = array[i];

            if( temNum % 6 == 0) {

                tip = tip + temNum +" ";

            }

        }

        System.out.print(tip);

    }

    // 将数组第一个数字和最后一个数字对调

    public static void exchange(int[] array) {

        String tip = "数组第一个数字和最后一个数字对调之后的数组为：[";

        int tem = array[array.length - 1];//最后一个的值存起来

        array[array.length - 1] = array[0];

        array[0] = tem;

        for(int i = 0; i<array.length; i++) {

            int temNum = array[i];

            tip = tip + temNum;

            if(i < array.length-1) {

                tip = tip + ",";

            }

        }

        System.out.print(tip+"]");

    }

    // 将数组的元素倒序排列

    public static void desc(int[] array) {

        String tip = "数组的元素倒序排列为：[";

        for(int i = 0; i<array.length/2; i++) {

            int tem = array[i];

            array[i] = array[array.length - i - 1];

            array[array.length - 1 - i] = tem;

        }

        for(int i = 0; i<array.length; i++) {

            int temNum = array[i];

            tip = tip + temNum;

            if(i < array.length-1) {

                tip = tip + ",";

            }

        }

        System.out.print(tip+"]");

    }

    //求1000以内的质数，存放到数组中

    public static void prime() {

        String tip = "1000以内的质数组合成的数组为：[";

        int[] prime = new int[50]; // 最多存放50个

        int count = 0;

        for(int i = 2;i <= 1000;i++) {

            boolean isPrime = true;

            for(int k = 2;k < i;k++) {

                if(i % k == 0) {

                    isPrime = false;

                    break;

                }

            }

            if(isPrime) {

                prime[count] = i;

                count++;

                if(count >= prime.length) {

                    break;

                }

            }

        }

        for(int i = 0; i < count; i++) {

            int temNum = prime[i];

            tip = tip + temNum;

            if(i < count-1) {

                tip = tip + ",";

            }

        }

        System.out.print(tip+"]");

    }

    // 主函数

    public static void main(String[] args) {

        // System.out.println("helloworld");

        int[] array = { 29, 90, 48, 92};

        // 调用

        print(array);

        System.out.print("\n");

        sixMultiple(array);

        System.out.print("\n");

        exchange(array);

        System.out.print("\n");

        desc(array); // 由于数组时引用类型，所以此处是数组值受exchange(array)方法的影响值为[92,90,48,29]

        System.out.print("\n");

        prime();

    }

// 上述运行结果

数组中每个元素分别为：29 90 48 92

6的倍数有：90 48

数组第一个数字和最后一个数字对调之后的数组为：[92,90,48,29]

数组的元素倒序排列为：[29,48,90,92]

1000以内的质数组合成的数组为：[2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,211,223,227,229]

}