云南大学JAVA程序设计实验四

实验报告
序号：实验老师：陆歌皓
课程名称：JA V A程序设计实验实验名称：lab4
学号：20111120279 姓名：李张昱
一、实验目的练习Java基本编程结构，包括字符串，输入输出等。

二、实验内容
1.Program 1
Write a program called String1.java and do the following:
Create a String object that accepts input from the user. Referencing the JDK docs, execute 2 different methods on the String. Print the results of the methods. Result:
Input a string:
How are you
length of string is 11
first 5 bytes of string are How a
根据实验要求写了以下程序：
package lab4;
import java.util.*;
public class String1 {
public static void main(String[] args){
Scanner in=new Scanner(System.in);
System.out.println("Input a string:");
String str=in.nextLine();
int n=str.length();
String substr=str.substring(0,5);
System.out.println("lenth of string is "+n);
System.out.println("first 5 bytes of string are "+substr);
}
}
2.Program 2
Write a program called StringTokenizer1.java that accepts a string, looks for commas within the string, and breaks the string up into the parts separated by the comma.
For example, the string "Kunming, Yunnan, China" would return three strings: String1 = "Kunming"
String2 = "Yunnan"
String3 = "China"
根据实验要求写了以下程序：
package lab4;
import java.util.*;
public class StringTokenizer1 {
public static void main(String[] args){
Scanner in=new Scanner(System.in);
System.out.println("Please input a string seperated by comma:");
String str=in.nextLine();
String [] a=str.split(",");
for(int i=0;i<a.length;i++)
System.out.println("String"+(i+1)+"="+a[i]);
}
}
3.Program 3
Design and write a Java class named SalesArray.java that will:
1.Declare a two-dimensional integer array named sales. Populate the first four columns using the
following data.
Quarter 1Quarter 2Quarter3Quarter 4Total Dept. 1750660910800
Dept. 2800700950900
Dept. 3700600750600
Dept. 48508001000950
Dept. 5900800960980
Total
2.Write a loop to compute and populate the total column. Within the loop, dispaly each
department total as it is computed.
3.Write a loop to compute and populate the total row. Within the loop, display each quarter's total
as it is computed.
根据实验要求写了以下程序：
package lab4;
public class SalesArray {
public static void main(String[] args) {
int[][] a=
{
{750, 660, 910, 800},
{800, 700, 950, 900},
{700, 600, 750, 600},
{850, 800, 1000,950},
{900, 800, 960, 980}
};
String[] str={" ","Quarter1 ","Quarter2 ","Quarter3 ","Quarter4","Total "};
for (int j = 0; j <str.length; j++)
System.out.printf("%9s",str[j]);
System.out.println( );
int total=0;
int total2=0;
int total3=0;
for(int i=0;i<a.length;i++){
System.out.print("Dept."+(i+1)+":");
for(int j=0;j<a[i].length;j++){
System.out.printf("%9d", a[i][j]);
total+=a[i][j];
total3+=a[i][j];
}
System.out.println(" "+total);
total=0;
}
System.out.print("Total :");
for(int i=0;i<a[0].length;i++){
for(int j=0;j<a.length;j++){
total2+=a[j][i];
}
System.out.printf("%9d", total2);
total2=0;
}
System.out.printf("%9d", total3);
}
}
三、数据记录和计算
Program 1运行结果:
Program 2运行结果:
Program 3运行结果:
四、结论
通过这次实验，掌握了java中二维数组的操作方法，巩固了循环方法的使用。

指导教师签名：陆歌皓。