我有两个不同的班级,学生和学生考试 - 学生班有;
public class Student {
// Data Members
private String name; // The name of this student
private long idNumber; // The ID number of this student
// Constructs a new Student with passed name and ID number parameters.
public Student(String studentName, long studentIDNumber) {
name = studentName;
idNumber = studentIDNumber;
}
// Returns the name of this student.
public String getName() {
return name;
}
// Returns the ID number of this student.
public long getIDNumber() {
return idNumber;
}
// Sets the name of this student.
public void setName(String studentName) {
name = studentName;
}
// Sets the ID number of this student.
public void setIDNumber(long studentIDNumber) {
idNumber = studentIDNumber;
}
@Override
public String toString(){
return "Name: " + this.name;
}
} // end class
StudentTest类有3种不同的方法,1。要求用户输入数组的大小,然后创建一个类型为Student的数组,2。要求用户使用名称和ID号填充数组, 3.显示数组的内容。
import java.util.Scanner;
public class StudentTest {
// Main method.
public static void main(String [] args) {
Student[] students = createArray();
populateArray(students);
displayArray(students);
}
// Method that asks user for size of array.
public static Student[] createArray() {
System.out.println("Enter size of array: ");
Scanner userInputEntry = new Scanner(System.in);
int inputLength = userInputEntry.nextInt();
Student students[] = new Student[inputLength];
return students;
}
// Method that asks user to populate array.
public static void populateArray(Student [] array) {
for(int i = 0; i < array.length; i++) {
array[i] = new Student();
System.out.println("Enter student name: ");
Scanner userInputEntry = new Scanner(System.in);
array[i].setName(userInputEntry.next());
System.out.println("Enter student ID number: ");
array[i].setIDNumber(userInputEntry.nextLong());
}
}
// Method that displays contents of array.
public static void displayArray(Student[] array) {
for(int i = 0; i < array.length; i++){
System.out.println(array[i].toString());
}
}
}
当我尝试运行它时,我收到有关
的错误 array[i] = new Student();
在第二种方法的for循环中。
答案 0 :(得分:3)
您希望如何运作?
@Override
public void toString(){
return "Name: " + this.name;
}
它应该给你一个编译错误。您正在尝试发回字符串,返回类型为空。
将其更改为
@Override
public String toString(){
return "Name: " + this.name;
}
将主要方法更改为
// Main method.
public static void main(String [] args) {
Student[] students = createArray();
populateArray(students);
displayArray(students)
}