软件工程第二次作业

 1 package work;
 2 
 3 import java.util.Scanner;
 4 
 5 import java.util.Arrays;//导入支持此次程序的JAVA包
 6 
 7 public class work22 {
 8      public static void main(String[] args) {
 9          int [] array1 ={-2574,-4010,8243,771,2447,-5197,2556,8044,3314,
10                  3617,6065,-2817,3131,6318,2186,-113,629,-2582,-37,
11                  -1520,164,2055,-5936,5912,1717,5988,4781,5757,892,
12                  -4394,8034,2213,-1080,-2080,5364,106,2657,566,3940,
13                  -5116,4583,1806,6555,2621,-7197,528,1626,18,1049,
14                  6243,3198,4397,-1325,9087,936,-6291,662,-178,135,
15                  -3473,-2385,-165,1713,-7949,-4234,1138,2212,104,
16                  6968,-3632,3801,1137,-1296,-1215,4272,6223,-5922,
17                  -7723,7044,-2938,-8180,1356,1159,-4022,-3713,1158,
18                  -8715,-4081,-2541,-2555,-2284,461,940,6604,-3631,3802,-2037,-4354,-1213,767};//定义数组并赋值，属于静态数组
19          int sum=0;
20          Scanner scanner = new Scanner(System.in) ;//要从键盘输入数据，采用Scanner类的nextInt()方法         
21          System.out.println("请输入一个起始数：");
22          int n=scanner.nextInt();
23          System.out.println("请输入一个终止数：");
24          int t=scanner.nextInt();
25          System.out.println("起始数："+n+"终止数："+t);
26          for(int i =n;i<=t;i++){//用for语句来在起始数和终止数中做一个循环加法。
27          sum+=array1 [i] ;
28          System.out.println("sum="+sum);
29          
30      }
31      }
32  }

运行结果演示：

此处运行结果让我感到非常奇怪，为什么会有多行结果输出。重新翻看书本，发现for语句的循环出了点问题。经改正后运行结果如下：

问题在与for语句循环中：

for(int i =n;i<=t;i++){
         sum+=array1 [i] ;}
         System.out.println("sum="+sum);
for(int i =n;i<=t;i++){
         sum+=array1 [i] ;
         System.out.println("sum="+sum);
}

for语句循环中一个{}的错误。

二维数组：

package work;

import java.util.Scanner;

public class work2a {public static void main(String[]args){
    int[][] array2={{-2574,-4010,8243,771,2447,-5197,2556,8044,3314,3617,6065,-2817,3131,6318,2186,-113,629,-2582,-37,-1520,164,2055,-5936,5912,1717,5988,
            4781,5757,892,-4394,8034,2213,-1080,-2080,5364,106,2657,566,3940,-5116,4583,1806,6555,2621,-7197,
            528,1626,18,1049,6243,3198,4397,-1325,9087,936,-6291,662,-178,135,-3473,-2385,-165,1713,-7949,-4234,
            1138,2212,104,6968,-3632,3801,1137,-1296,-1215,4272,6223,-5922,-7723,7044,-2938,-8180,1356,1159,-4022,
            -3713,1158,-8715,-4081,-2541,-2555,-2284,461,940,6604,-3631,3802,-2037,-4354,-1213,767},
         {2740,-4182,-5632,-2966,-1953,567,-8570,1046,2211,1572,-2503,-1899,3183,-6187,3330,3492,-464,-2104,316,8136,470,50,466,
             -1424,5809,2131,6418,-3018,6002,-8379,1433,1144,2124,1624,-602,-5518,5872,870,-5175,-3961,-427,-6284,2850,
            481,6175,141,-766,-1897,-748,-4248,366,4823,3003,1778,3256,2182,2253,5076,5540,-2650,2451,-1875,5482,-6881,
            -329,-969,-8032,-2093,612,1524,-5492,5758,-7401,-5039,3241,6338,3581,4321,-1072,4942,2131,210,-7045,-7514,7450,
            -1142,-2666,-4485,-639,2121,-5298,-3805,-1686,-2520,-1680,2321,-4617,-1961,2076,7309}};
    
int sum=0;
Scanner scanner = new Scanner(System.in) ;//与上一个程序相同，都需要Scanner类。
System.out.println("请输入一个起始数x1：");//与上一个程序不同，因为是二维数组，所以先输入两个x轴或者y轴的数，再相加。
int x1=scanner.nextInt();
System.out.println("请输入一个终止数x2：");
int x2=scanner.nextInt();
System.out.println("起始数："+x1+"终止数："+x2);
System.out.println("请输入一个起始数y1：");
int y1=scanner.nextInt();
System.out.println("请输入一个起始数y2：");
int y2=scanner.nextInt();
System.out.println("起始数："+y1+"终止数："+y2);

for(int i=x1;i<=x2;i++)for(int j=y1;j<=y2;j++){
sum+=array2[i][j];}
System.out.println("sum="+sum);
}
}

下面是演示结果：

 

个人经验总结：

     我觉得是在代码的优化上，我们还需要更加努力，比如说java如何读取excel中的数据或者xml文件中的数据，在网上找到的资料也是看的云里雾里。毕竟我的基础还是太薄弱了。在写这些代码的过程中，尝试了很多不同的表现方式。比如说最后的计算部位，尝试过用for-if语句。发现自己对if语句的认识非常之少，所以放弃了多种组合语句计算的方式，还需要多多的回顾以前javaEE的教程。只有在基础上的运用达到娴熟的程度，才能接触到更高层次的语法。在写第一个程序的时候，我在开头导入了java.util.Arrays这个包,但是当我把整个程序全部完成后，这个包也没被使用过。可能是因为我只是将数组中的数据手动COPY了上去，没有用到数组引用或者遍历的效果。所以在第二个程序中并没有导入这个包，最后程序也是顺利的运行了。其中还有很多细小的错误，都被逐个的纠正了。所以，我觉得写代码是一件细活，不能急躁的想要出结果，而是一步步的实现我所需要的需求，最终组合起来就是我想要的结果。