Java第八周上机练习+作业

上机练习

1.编写一个简单程序,要求数组长度为5,分别赋值10,20,30,40,50,在控制台输出该数组的值。(知识点:数组定义和创建、一维数组初始化)

packageaaa;

publicclass Test1 {

    /**
     * @paramargs
     */
    publicstaticvoid main(String[] args) {
        // TODO Auto-generated method stub
        int []a={10,20,30,40,50};
        for (int i = 0; i <a.length; i++) {
            System.out.println(a[i]);
        }
    }

}

 

2.将一个字符数组的值(neusoft)拷贝到另一个字符数组中。(知识点:数组复制)

    /**
     * @paramargs
     */
    publicstaticvoid main(String[] args) {
        // TODO Auto-generated method stub
        char []x={'n','e','u','s','o','f','t'};
        char []y=newchar[x.length];
        System.arraycopy(x, 0, y, 0,x. length);
        for(char i:y){
            System.out.println(i);
        }

    }

}

 

 

3.给定一个有9个整数(1,6,2,3,9,4,5,7,8)的数组,先排序,然后输出排序后的数组的值。(知识点:Arrays.sort排序、冒泡排序)

packageaaa;

publicclass Test2 {

    /**
     * @paramargs
     */
    publicstaticvoid main(String[] args) {
        // TODO Auto-generated method stub
        int[] a = { 1, 6, 2, 3, 9, 4, 5, 7, 8 };
        for (int i = 0; i <a.length - 1; i++) {
            for (int j = 0; j <a.length - 1 - i; j++) {
                if (a[j] > a[j + 1]) {
                    int temp = a[j];
                    a[j] = a[j + 1];
                    a[j + 1] = temp;

                }

            }
        }
        for (int i : a) {
            System.out.println(i);
        }

    }

}

 

packageaaa;

importjava.util.Arrays;

publicclass Test2 {

    /**
     * @paramargs
     */
    publicstaticvoid main(String[] args) {
        // TODO Auto-generated method stub
        int[] a = { 1, 6, 2, 3, 9, 4, 5, 7, 8 };
        for (int i = 0; i <a.length - 1; i++) {
            for (int j = 0; j <a.length - 1 - i; j++) {

            }
        }
        Arrays.sort(a);
        for (int i : a) {
            System.out.println(i);
        }
    }

}

4.输出一个double型二维数组(长度分别为5、4,值自己设定)的值。(知识点:数组定义和创建、多维数组初始化、数组遍历)

packageaaa;

importjava.util.Arrays;

publicclass Test2 {

    /**
     * @paramargs
     */
    publicstaticvoid main(String[] args) {
        // TODO Auto-generated method stub
        double a[][] = newdouble[5][4];
        for (int i = 0; i <a.length; i++) {
            for (int j = 0; j < a[i].length; j++) {
                a[i][j] = i;
            }
        }

        for (int i = 0; i <a.length; i++) {
            for (int j = 0; j < a[i].length; j++) {
                System.out.print(a[i][j] + "  ");
            }
            System.out.println();

        }

    }
}

 5.在一个有8个整数(18,25,7,36,13,2,89,63)的数组中找出其中最大的数及其下标。(知识点:数组遍历、数组元素访问)

packageaaa;

publicclass Test3 {

    /**
     * @paramargs
     */
    publicstaticvoid main(String[] args) {
        // TODO Auto-generated method stub
        int []a={18,25,7,36,13,2,89,63};
        int max=a[0];
        int i;
        inty;
        for ( i = 0; i <a.length; i++) {
            if(a[i]>max)
                max=a[i];
        }
        y=i-1;
        System.out.println("最大值是"+max);
        System.out.println("下标是"+y);
    }

}

 

 

作业

6.将一个数组中的元素逆序存放(知识点:数组遍历、数组元素访问)

import java.util.Scanner;


public class Text1 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入数组中的元素个数");
        int a = input.nextInt();
        int b[] = new int[a];
        System.out.println("输入数组元素:");
        for (int i = 0; i < a; i++) {
            b[i] = input.nextInt();

        }
        for (int j = a - 1; j > 0; j--) {
            System.out.print(b[j]);
        }
        System.out.println(b[0]);
    }

}

 

 7.将一个数组中的重复元素保留一个其他的清零。(知识点:数组遍历、数组元素访问)

public class Text2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
         int a[] = new int[] { 6,8,8,5,5,4,6};
            for (int i = 0; i < a.length; i++) {
                for (int j = 0; j < a.length; j++) {
                    if (a[i] == a[j] && i != j) {
                        a[j] = 0;
                    }
                }

            }
            for (int x: a) {
                System.out.print(x);
            }

    }

}

 

 

8.给定一维数组{ -10,2,3,246,-100,0,5},计算出数组中的平均值、最大值、最小值。(知识点:数组遍历、数组元素访问)

public class Text2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int a[] = new int[] { -10, 2, 3, 246, -100, 0, 5 };
        int sum = 0;
        int max = a[0];
        int min = a[0];
        for (int i = 0; i < a.length; i++) {
            sum += a[i];
            if (a[i] > max)
                max = a[i];
            if (a[i] < min)
                min = a[i];
        }
        int pj=sum/7;
        System.out.println("最大值是" + max);
        System.out.println("最小值是" + min);
        System.out.println("平均值是" + pj);

    }

}

 

 


9.使用数组存放裴波那契数列的前20项 ,并输出 1 1 2 3 5 8 13 21

public class Text2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
         int a[] = new int[20];
            a[0] = 1;
            a[1] = 1;
            for (int i = 2; i < a.length; i++) {
                a[i] = a[i - 1] + a[i - 2];
            }
            for (int i = 0; i < 8; i++) {
                System.out.println(a[i]);
            }
    }

}

 

 


10.生成一个长度为10的随机整数数组(每个数都是0-100之间),输出,排序后,再输出

 

import java.util.Arrays;
import java.util.Random;
import java.util.Scanner;

public class Text2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int a[]=new int[10];
        Random x=new Random();
        System.out.println("创建的100以内的随机数");
        for (int i = 0; i < a.length; i++) {
            a[i]=x.nextInt(101);
        }
        for (int i = 0; i < a.length; i++) {
            System.out.println(a[i]);
        }
        System.out.println("经排序后                          ");
        Arrays.sort(a);
        for (int i = 0; i < a.length; i++) {
            System.out.println(a[i]);
        }
    }

}

 

posted @ 2021-04-23 18:18  小Q爱吃巧克力  阅读(88)  评论(0编辑  收藏  举报