第七周Java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 work7;

public class test1 {

    /**
     * @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 work7;

import java.util.Scanner;

public class test2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
   Scanner input=new Scanner(System.in);
   int []a=new int[5];
   for (int i = 0; i < a.length; i++) {
    a[i]=input.nextInt();
}
   System.out.println("控制台输出");
   for (int i = 0; i < a.length; i++) {
    System.out.print(" "+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 work7;

public class test3 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
     String []a={"c","h","i","n","a"};
     for (int i = 0; i < a.length; i++) {
        System.out.print(a[i]);
       }
    }

}

 

 

 

4.输入5个学生成绩，求总分和平均分

 

 

package work7;

import java.util.Scanner;

public class test4 {

    /**
     * @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5位学生的成绩");
   int []a=new int [5];
   double sum=0;
   double pj=0;
   for (int i = 0; i < a.length; i++) {
    a[i]=input.nextInt();
    sum+=a[i];
    pj=sum/5;
        }
   System.out.println("总分为"+sum);
   System.out.println("平均分为"+pj);
    }

}

 

 

 

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

 

package work7;

import java.util.Scanner;

public class test5 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
  Scanner input=new Scanner(System.in);
  int a[]={12,53,23,44,53};
  System.out.println("for输出");
  for (int i = 0; i < a.length; i++) {
    System.out.print(" "+a[i]);
             }
  System.out.println("\nforeach输出");
  for (int i : a) {
    System.out.print(" "+i);
         }
  System.out.println("\n倒序输出");
  for (int i = 4; i >=0; i--) {
    System.out.print(" "+a[i]);
      }
   }

}

 

 

 

作业

1.定义一个整型数组，赋值(动态静态都可以)后求出奇数个数和偶数个数

 

package work7;

public class work6 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub     
     int a[]={11,22,33,44,55};
     int c=0;
     int b=0;
     for (int i = 0; i < a.length; i++) {
        if (a[i]%2==0) {
            b++;
                 }
        if (a[i]%2!=0) {
            c++;
             }
        }
     System.out.println("偶数个数为"+b);
     System.out.println("奇数个数为"+c);
    }

}

2.生成一个100长度数组，里面的数分别是1-100，并输出

 

package work7;

public class work7 {

    /**
     * @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;
                              }
     for (int i =0; i < a.length; i++) {
         if (i<33) {
             System.out.print(" "+a[i]);
                           }
         else if (i==33) {
            System.out.println(" "+a[i]);
                       }
        else if (i<66) {
            System.out.print(" "+a[i]);
                   }
        else if (i==66){
            System.out.println(" "+a[i]);
              }
        else if (i<=99) {
            System.out.print(" "+a[i]);
           }
        else if (i==100){
            System.out.println(" "+a[i]);
         }
        else{}
      }
    
   }

}

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 work7;

import java.util.Scanner;

public class work8 {

    /**
     * @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位学生成绩");
   double []a=new double [10];
   for (int i = 0; i < a.length; i++) {
    a[i]=input.nextDouble();
                     }
   for (int i = 0; i < a.length; i++) {
    a[i]=a[i]+5;
    if (a[i]>100) {
        a[i]=100;
               }
          }
   System.out.println("加5分后");
   for (int i = 0; i < a.length; i++) {
        System.out.print(a[i]+" ");
       }
    }

}