我想写一些java代码,但我得到一个异常。 我的问题是,我得到一个空指针异常,当我尝试添加运动员 程序是接受运动员和计算平均得分这里 是我的代码arraylist不打印第一个元素
public class AthleteTest {
final int MAX_ATHELETE = 200;
private int count=0;
Athlete[] at = new Athlete[MAX_ATHELETE];
Scanner sc = new Scanner(System.in);
public void addAthletes(){
char add = 'Y';
while(add == 'Y'){
System.out.println("name:");
String name = sc.nextLine();
at[count].setName(name);
//Get athlete's Id number
System.out.println("id :");
int id = sc.nextInt();
at.setId(id);
//sc.nextLine();
count++;
System.out.println("Would you like to add another athlete? Y/N");
add = Character.toUpperCase(sc.next().charAt(0));
sc.nextLine();
}
}
}
my Athlete class is as follow
public class Athlete {
private String name;
private int id;
private double [] grades;
public Athlete(){
this.name = null;
this.id= 0;
}
public Student(String name, int id){
this.name = name;
this.id= id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
}
ArrayList在哪里? –
'at [count] .setName(name)' - 是在[count]'初始化?如果不是,那就是为什么你会得到'NullPointerException'。你应该在[count] = new Athlete()'首先执行 – 2017-04-04 17:40:44
是的,我做过了,但它仍然给我一个空指针异常 –