Question

在数组列表java中，如何获取以字母“ T”开头的教师姓名列表。我想显示教师的名单名称。如果没有退出教师列表，则会显示“没有老师的名字以字母T开头”。该程序是关于抽象和多态的。这是我的代码

class teacher 
package Tinhdahinh;
public abstract class Teacher {
//Properties
int code;
String name;

//method

public Teacher() {
}

public Teacher(int code, String name) {
    this.code = code;
    this.name = name;
}

public int getCode() {
    return code;
}

public void setCode(int code) {
    this.code = code;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}
// ham hien thi thong tin

void show(){
    System.out.print(this.getCode() + "\t" + this.getName());
}

//Ham abstract tinh luong
abstract double getSalary();
}

类接口管理方法

@Override
public void countNameStarByt(ArrayList<Teacher> lst) {
  int count = 0;
  for (Teacher teacher : lst) {
        if(teacher.getName().startsWith("T")){
            count++;
           // teacher.show();
        }
             if(count > 0){
                 System.out.println(count);
                teacher.show(); 
    }
        else{
            System.out.println("No teacher has name starting with letter 
'T'.");
             break;
            }

  }
    //System.out.println("");
}

public class Main {
public static void main(String[] args) {
 Quanly Q = new Quanly();
    ArrayList<Teacher> lst = new ArrayList();
    Q.inputList(lst, 3);
   System.out.println();
    System.out.println("Is there any teachers has name starting with letter 
'T': ");
    Q.countNameStarByt(lst);
}
}

Answer 1

使用count是错误的。如果count大于零，则代码将打印出每个Teacher对象，无论其名称是否以T开头。如果count为零，即使列表中有有效的对象，循环也会终止。

尝试：

@Override
public void countNameStarByt(ArrayList<Teacher> lst) {
   int count = 0;
   for (Teacher teacher: lst) {
      if(teacher.getName().startsWith("T")){
        count++;
        teacher.show();
      } 
   }
   if (count == 0) {
      System.out.println("No teacher has name starting with letter 'T'.");
   }
}

Answer 2

我可以在您的代码中看到的问题是您编写了break语句的其他部分。因此，在第一次迭代中，如果未找到列表，则控件将位于else中并中断循环。

这可以为您工作

for (Teacher teacher : lst) {
    if(teacher.getName().startsWith("T")){
        count++;
        System.out.println(count);
        teacher.show();
    }
}
if(count==0){
    System.out.println("Teacher not found");
}

Answer 3

while (Teacher teacher: lst) {
if(teacher.getName().startsWith("T")){
    count++;
    System.out.println(count);
    teacher.show();
   }
 }
    if(count==0){
    System.out.println("Teacher not found");
}

如何在数组列表中以字母T开头并显示老师姓名的名称字符串？

3 个答案: