Java第七周作业

上机练习：

1.编写一个简单程序，要求数组长度为5，静态赋值10，20，30，40，50，在控制台输出该数组的值

 

package Work;

public class Work1 {

    /**
     * @param args
     */
    public static void 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.编写一个简单程序，要求数组长度为5，动态赋值，并在控制台输出该数组的值

package Work;

import java.util.Scanner;

public class Work2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int []a=new int[5];
        Scanner input=new Scanner(System.in);
        for (int i = 0; i < a.length; i++) {
            System.out.println("请输入第"+(i+1)+"个赋值");
            a[i]=input.nextInt();
        }
        for(int i=0;i< a.length; i++) {
            System.out.println("第"+(i+1)+"个赋值"+a[i]);
        }

    }
    
}

 

 3.定义字符型数组，分别存储c、h、 i、n、a 并在控制台输出

package Work;

public class Work3 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        char a[]={'c','h','n','a'};
        for(char i:a){
            System.out.println(i);
        }

    }

}

 

 4.输入5个学生成绩，求总分和平均分

package Work;

import java.util.Scanner;

public class Work4 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int sum=0;
        double pj;
        int []a=new int[5];
        Scanner input=new Scanner(System.in);
        for (int i = 0; i < a.length; i++) {
            a[i]=input.nextInt();
        }
        for (int i = 0; i < a.length; i++) {
            sum+=a[i];
        }
        pj=sum/5;
        System.out.println(sum);
        System.out.println(pj);
    }

}

5.定义数组{12,53,23,44,53} 用for和foreach分别输出，再倒序输出 

public class Work5 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int[] a = { 12, 53, 23, 44, 53 };
        System.out.println("for输出");
        for (int i = 0; i < a.length; i++) {
            System.out.println("正序输出为" + a[i]);
        }
        System.out.println("foreach输出");
        for (int i : a) {
            System.out.println("正序输出为" + i);
        }
        System.out.println("for倒叙输出");
        for (int i = a.length - 1; i >= 0; i--) {
            System.out.println("倒叙输出为" + a[i]);
        }
    }

}

 

 作业：
1.定义一个整型数组，赋值后求出奇数个数和偶数个数

package Homework;

import java.util.Scanner;

public class Homework1 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int[] a = new int[10];
        int js = 0;
        int os = 0;
        Scanner input = new Scanner(System.in);
        for (int i = 0; i < a.length; i++) {
            System.out.println("请输入第" + (i + 1) + "个数");
            a[i] = input.nextInt();
        }
        for (int i = 0; i < a.length; i++) {
            if (a[i] % 2 == 1)
                js += 1;
            else
                os++;
        }
        System.out.println("奇数个数为" + js + "偶数个数为" + os);

    }

}

 

 2.生成一个100长度数组，里面的数分别是1-100，并输出

package Homework;

import java.util.Scanner;

public class Home2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int []a=new int[100];
        for (int i = 0; i < a.length; i++) {
            a[i]=i+1;
            System.out.println(a[i]);
        }
    }
    
}

2.定义一个数组，求数组中的最大值和最小值

package Homework;

import java.util.Scanner;

public class Home2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        int[] a = new int[10];
        System.out.println("请任意输入10个数");
        for (int i = 0; i < a.length; i++) {
            a[i] = input.nextInt();
        }
        int max = a[0];
        int min = a[0];
        for (int i = 0; i < a.length; i++) {
            if (a[i] > max) {
                max = a[i];
            }
            if (a[i] < min) {
                min = a[i];
            }
        }
        System.out.println("数组中的最大值：" + max);
        System.out.println("数组中的最小值：" + min);
    }

}

3.定义一个double数组，存放10个学生的成绩，给所有同学加5分，不能超过100分。

 

package Class;

import java.util.Scanner;

public class Exe3 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("请输入10个学生成绩");
        double[] a = new double[10];
        for (int i = 0; i < a.length; i++) {
            a[i] = input.nextDouble();
        }
        System.out.println("加分后的成绩为：");
        for (int i = 0; i < a.length; i++) {
            if (a[i] < 0 || a[i] > 100) {
                System.out.println("输入错误，请重新输入");
                a[i] = input.nextDouble();
            }
            a[i] += 5;
            if (a[i] > 100) {
                a[i] = 100;
            }
            System.out.println(a[i]);
        }
    }

}