在 java 中分配和返回对象
Assigning and returning objects in java
我试图用调用 getStudent 方法后返回的 Student 对象分配临时数组中的当前数组元素....我调用了 getStudent 方法(第 2 步)并让 temp[ i] = 分配临时数组中的当前元素,但无法弄清楚它应该是什么 = 将它与返回的 Student 对象配对。当使用 getStudent() 和 运行 程序时,输出是输入学生人数,用户输入人数,仅此而已,它不要求用户输入姓名等,我不确定第 2 步是否有问题,或者是否完全存在其他问题。
import java.util.Scanner;
public class Students
{
private static Scanner input = new Scanner(System.in);
public static void main(String[] args)
{
Student[] students;
students = getStudents();
printStudents(students);
}
private static Student[] getStudents()
{
Student[] temp;
int how_many;
System.out.print("How many students? ");
how_many = input.nextInt();
purgeInputBuffer();
temp = new Student[input.nextInt()]; // Step 1 ???
for (int i = 0; i < temp.length; i++)
{
getStudent(); // Step 2
temp[i] = ; // <----------
}
return temp; // Step 3
}
private static Student getStudent()
{
String name,
address,
major;
double gpa;
System.out.print("Enter name: ");
name = input.nextLine();
System.out.print("Enter address: ");
address = input.nextLine();
System.out.print("Enter major: ");
major = input.nextLine();
System.out.print("Enter GPA: ");
gpa = input.nextDouble();
purgeInputBuffer();
return new Student (name, address, major, gpa); // Step 4
}
private static void printStudents(Student[] s)
{
System.out.println();
for (int i = 0; i < s.length; i++) // Step 5
{
System.out.println(getStudent()); // Step 6
}
}
private static void purgeInputBuffer()
{
// ----------------------------------------------------
// Purge input buffer by reading and ignoring remaining
// characters in input buffer including the newline
// ----------------------------------------------------
input.nextLine();
}
}
所以第一个问题先上线:
temp = new Student[input.nextInt()];
在那一行中,您已经要求用户输入多少学生并将其存储在 how_many
中。所以我假设你想改为:
temp = new Student[how_many];
还有我在评论中说的:
但也请务必查看您的 private static void printStudents(Student[] s)
方法,并准确地看一下//第 6 步,我认为这不是您想要的方式。相反,您希望 System.out.println(s[i]);
而不是 System.out.println(getStudent());
为了使我的代码替换正常工作,尽管您需要重写 toString 方法以便它实际显示信息
import java.util.Scanner;
public class Students
{
private static Scanner input = new Scanner(System.in);
public static void main(String[] args)
{
Student[] students;
students = getStudents();
printStudents(students);
}
private static Student[] getStudents()
{
Student[] temp;
int how_many;
System.out.print("How many students? ");
how_many = input.nextInt();
purgeInputBuffer();
temp = new Student[input.nextInt()]; // Step 1 ???
for (int i = 0; i < temp.length; i++)
{
getStudent(); // Step 2
temp[i] = ; // <----------
}
return temp; // Step 3
}
private static Student getStudent()
{
String name,
address,
major;
double gpa;
System.out.print("Enter name: ");
name = input.nextLine();
System.out.print("Enter address: ");
address = input.nextLine();
System.out.print("Enter major: ");
major = input.nextLine();
System.out.print("Enter GPA: ");
gpa = input.nextDouble();
purgeInputBuffer();
return new Student (name, address, major, gpa); // Step 4
}
private static void printStudents(Student[] s)
{
System.out.println();
for (int i = 0; i < s.length; i++) // Step 5
{
System.out.println(getStudent()); // Step 6
}
}
private static void purgeInputBuffer()
{
// ----------------------------------------------------
// Purge input buffer by reading and ignoring remaining
// characters in input buffer including the newline
// ----------------------------------------------------
input.nextLine();
}
}
所以第一个问题先上线:
temp = new Student[input.nextInt()];
在那一行中,您已经要求用户输入多少学生并将其存储在 how_many
中。所以我假设你想改为:
temp = new Student[how_many];
还有我在评论中说的:
但也请务必查看您的 private static void printStudents(Student[] s)
方法,并准确地看一下//第 6 步,我认为这不是您想要的方式。相反,您希望 System.out.println(s[i]);
而不是 System.out.println(getStudent());
为了使我的代码替换正常工作,尽管您需要重写 toString 方法以便它实际显示信息