[求助]为何我编的程序只查找出第一个学生信息？_Java相关

[求助]为何我编的程序只查找出第一个学生信息？

题目：
编写一个学生类，要求有学号、姓名、性别、班级字段。要求实现构造函数和默认构造函数，并实现show方法用来显示学生基本信息。创建一个学生类数组（长度为5），并在数组中存放在3个学生信息。从键盘输入学号，把相应的学生信息查找并显示出来。

[此贴子已经被作者于2006-6-5 22:17:20编辑过]

搜索更多相关的解决方案: 学生

----------------解决方案--------------------------------------------------------

程序代码：

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class StudentTest {
public static void main(String[] args) {
int id = 0;
try {
System.out.print(\"Enter id: \");

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

id = Integer.valueOf(br.readLine());
} catch(Exception e) {

}

StudentManager[] student = new StudentManager[5];

student[0] = new StudentManager(1,\"a\",\"W\",\"001\");
student[1] = new StudentManager(2,\"b\",\"M\",\"003\");
student[2] = new StudentManager(3,\"c\",\"W\",\"001\");

System.out.println(student[id-1].show());
}
}

class StudentManager {
private int id;

private String studentName,studentSex,studentClass;

StudentManager(int id,String studentName,String studentSex,String studentClass) {
this.id = id;
this.studentName = studentName;
this.studentSex = studentSex;
this.studentClass = studentClass;
}

StudentManager() {

}

String show() {
return id + \" , \" + studentName + \" , \" + studentSex + \" , \" + studentClass;
}
}

要的是这样的效果？

----------------解决方案--------------------------------------------------------

import java.util.*;
import java.io.*;
class Student
{
String name;
String num;
String sex;
String cla;
public Student(String name,String num,String sex,String cla)
{
this.name=name;
this.num=num;
this.sex=sex;
this.cla=cla;
}
public Student()
{
}
public String show()
{
return "name=" + name + " "+ "num=" + num + " " +"sex=" +
sex +" " + "cla=" +cla;
}
public String getNum()
{
return num;
}
}

class Collage extends Student
{
String department;
public Collage(String name,String num,String sex,String cla,
String department)
{
super(name,num,sex,cla);
this.department=department;
}
public String show()
{
return super.show()+"department=" + department;
}
}
public class StudentTest
{

public static void main(String s[])
{
String S=" ";
String sNum=" ";
Student e[]=new Student[3];
e[0]=new Student("李四","001","男","1班");
e[1]=new Student("张三","002","男","1班");
e[2]=new Student("李强","003","女","2班");
for (int i=0;i<e.length;i++)
{
String sBuf=e[i].show();
System.out.println(sBuf);
}
System.out.println("请输入学号：");
try
{
BufferedReader din=new BufferedReader(new InputStreamReader(System.in));
S=din.readLine();
}
catch (Exception b)
{
}
for(int i=0;i<e.length;i++)
{
sNum=e[i].getNum();
if((S.equals(sNum)))
{
System.out.println(e[i].show());
break;
}
else
{
System.out.println("对不起，你输入的学号不存在！");
break;
}
}
try
{
System.in.read();
}
catch (IOException c)
{
}
}
}

这个就是他的程序本来就应该是一个人啊你要想全出来就按着顺序打印就好了如果想从键盘输入的话加上个 while循环就可以了

----------------解决方案--------------------------------------------------------
if((S.equals(sNum)))
{
System.out.println(e[i].show());
break;
}
else
{
System.out.println("对不起，你输入的学号不存在！");
break;
}
程序块里加Break是什么意思啊，有用吗，还是编程习惯！
----------------解决方案--------------------------------------------------------

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class StudentTest {
public static void main(String[] args) {
int id = 0;
try {
System.out.print("Enter id: ");

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

id = Integer.valueOf(br.readLine());
} catch(Exception e) {

}

StudentManager[] student = new StudentManager[5];

student[0] = new StudentManager(1,"a","W","001");
student[1] = new StudentManager(2,"b","M","003");
student[2] = new StudentManager(3,"c","W","001");

System.out.println(student[id-1].show());
}
}

class StudentManager {
private int id;

private String studentName,studentSex,studentClass;

StudentManager(int id,String studentName,String studentSex,String studentClass) {
this.id = id;
this.studentName = studentName;
this.studentSex = studentSex;
this.studentClass = studentClass;
}

StudentManager() {

}

String show() {
return id + " , " + studentName + " , " + studentSex + " , " + studentClass;
}
}

这个程序运行不得啊

----------------解决方案--------------------------------------------------------

----------------解决方案--------------------------------------------------------
for(int i=0;i<e.length;i++)
{
sNum=e[i].getNum();
if((S.equals(sNum)))
{
System.out.println(e[i].show());
break;
}
else
{
System.out.println("对不起，你输入的学号不存在！");
break;
}
}

这一句出了问题,你在比较了一遍后就break了,所以后面的循环就没有进行了
你应该判断一下,当i=e.length的时候,还没有匹配上才输出一个"对不起,你输入的学号不存在"这句话.

----------------解决方案--------------------------------------------------------
for(int i=0;i<e.length;i++)
{
sNum=e[i].getNum();
if((S.equals(sNum)))
{
System.out.println(e[i].show());
break;
}
else
{
System.out.println("对不起，你输入的学号不存在！");
break;
}
}

这一句出了问题,你在比较了一遍后就break了,所以后面的循环就没有进行了
你应该判断一下,当i=e.length的时候,还没有匹配上才输出一个"对不起,你输入的学号不存在"这句话.

----------------解决方案--------------------------------------------------------