[英]How to return an anonymous instantiated object in java
在步骤4中,我必须使用输入的4个信息项返回匿名实例化的Student对象。 由于找不到任何解决此问题的论坛,因此我需要一些帮助来设置它或示例。
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();
temp[i] = getStudent(); // Step 2
}
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 ___________________________________________________; // Step 4
}
private static void printStudents(Student[] s)
{
System.out.println();
for (int i = 0; i < s.length; i++) // Step 5
{
System.out.println(______); // Step 6
}
}
private static void purgeInputBuffer()
{
// ----------------------------------------------------
// Purge input buffer by reading and ignoring remaining
// characters in input buffer including the newline
// ----------------------------------------------------
input.nextLine();
}
}
只是
return new Student(constructor args);
constructor args
是Student
构造函数需要的任何参数。
这里使用“匿名”不是标准的Java术语。 我想因为您没有将对象引用分配给局部变量,所以可以将其视为“匿名”。 由于在以下位置的getStudent()
中调用了getStudents()
,因此它不会长时间保持匿名状态
temp[i] = getStudent();
因此引用将立即保存(到数组中)。
“匿名”出现在术语“匿名子类”中,但这是您可能尚未涉及的完全不同的概念。
您可以将字段设为私有,并使用参数化的构造函数对其进行初始化。
public class Students
{
private static Scanner input = new Scanner(System.in);
private String name;
private String address;
private String major;
double gpa;
public Students(String name, String address, String major, double gpa) {
this.name = name;
this.address = address;
this.gpa = gpa;
this.major = major;
}
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();
temp[i] = getStudent(); // Step 2
}
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 Students(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(______); // Step 6
}
}
private static void purgeInputBuffer()
{
// ----------------------------------------------------
// Purge input buffer by reading and ignoring remaining
// characters in input buffer including the newline
// ----------------------------------------------------
input.nextLine();
}
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.