需要帮助使用数组对象显示数组的所有数据（不能使用数组列表）
Need help to show all data of the arrays using Array Object (Can't use Array List)
我正在创建一个学校系统，它显示所有 class 和学生的列表以及他们的成绩和总成绩**。
但现在我真的卡住了。我可以在列表中显示 class 中的所有数据，但我现在真的不知道该怎么做。请帮助我的代码。
在这段代码中，我使用数组来存储学生，年级，class姓名和class数量的数据。
ARRAYS FOR CLASS AND STUDENT:-
The class can store up to [10 class] but initial it with min 3 class
and not more than that max is 10 students can store up to [20 students]
and not more than that the max is 20
在此代码中不使用数组列表。
= 我想要的学校列表输出 =
在此输出中，名称按成绩升序排列，并在顶部按数字列出，其中显示 class 的总成绩最高。 用户询问是否返回功能选择
=== SCHOOL LISTS ===
1. Class Thunder with Total grade: 146
2. Class Lightning with Total grade: 103.9
3. Class Sunrise with Total grade: 115.5
--------------------
Class: Sunrise
Class quantity: 5
Student1: James Shawn
Grade: 75
Student2: Ali Pole
Grade: 30.5
Student3: Tong Kim
Grade: 10
Total Grade: 115.5
------------------------
Class: Thunder
Class quantity: 5
Student1: Mark Lee
Grade: 65.5
Student2: James Mic
Grade: 20.4
Student3: James Mic
Grade: 18.0
Total Grade: 103.9
------------------------
Class: Lightning
Class quantity: 5
Student1: Luke Kim
Grade: 90
Student2: Noth Shawn
Grade: 44
Student3: Lex Wale
Grade: 12
Total Grade: 146
Do you want to go back to the selection function?
Press Y or N:
//if yes they will go back to the functionSelection
//if no they will ask users if they want to exit the systems.
Do you want to exit (Y or N):
//if yes they will exit the systems
//if no they will go back to the functionSelection.
我的 JAVA 计划
学生 CLASS:-
import java.util.Comparator;
public class Student {
private String studentName;
private int grade;
public Student(String studentName, int score) {
this.studentName = studentName;
this.grade = grade;
}
public String toString() {
return "\nStudent Name: " + studentName + "\nGrade: " + grade;
}
public String getStudentName() {
return studentName;
}
public int getGrade() {
return grade;
}
public void setStudentName(String studentName) {
this.studentName = studentName;
}
public void setGrade(int grade) {
this.grade = grade;
}
}
//Sorting side
class sortGrade implements Comparator<Student> {
@Override
public int compare(Student a, Student b) {
return (a.getGrade() - b.getGrade());
}
}
CLASS CLASS:-
public class Class {
Student[] student;
private String className;
private int classQuantity;
private int totalGrade = 0;
//add student to the class
public void addNewStudent(String studentName, double grade) {
}
public double calculateTotalGrade() {
for (Student students : student) {
totalGrade += students.getGrade();
}
return Math.round(totalGrade * 10.0) / 10.0;
}
public Class(Student[] student,
String className, int classQuantity) {
this.student = student;
this.className = className;
this.classQuantity = classQuantity;
}
public Class(String className, int classQuantity) {
this.className = className;
this.classQuantity = classQuantity;
}
public String toString() {
String studentList = " ";
for (int i = 0; i < student.length; i++) {
studentList += "\n\tStudent " + (i + 1) + ": " + student[i].getStudentName()
+ "\n\tGrade: " + student[i].getGrade();
}
return "\nClass Name: " + className
+ "\nClass Quantity: " + classQuantity + "\n" + studentList;
}
}
主要驱动程序CLASS:-
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Scanner;
public class MainDriver {
private Object[] a;
void printSort(Student[] sortList) {
for (Object sort : a) {
System.out.print(sort + " ");
}
System.out.println();
}
public static void main(String[] args) {
int size = 10;
Class[] classroom = new Class[size];
Student[] studentList1 = {
new Student("Tong Kim", 10),
new Student("Ali Pole", 30),
new Student("James Shawn", 75)};
Student[] studentList2 = {
new Student("James Mic", 20),
new Student("Ho Kim", 18),
new Student("Mark Lee", 65)};
Student[] studentList3 = {
new Student("Luke Kim", 90),
new Student("Noth Shawn", 44),
new Student("Lex Wale", 12)
};
classroom[0] = new Class(studentList1, "Sunrise", 20);
classroom[1] = new Class(studentList2, "Thunder", 10);
classroom[2] = new Class(studentList3, "Lightning", 5);
Scanner input = new Scanner(System.in);
boolean functionSelection = true;
// Student[] SortList = studentList1;
while (functionSelection) {
System.out.println("=== SCHOOL SYSTEM === \n");
System.out.println("[1] Add New Class");
System.out.println("[2] Exit");
System.out.print("\nChoose a function: ");
//Check if it is other then number
if (!input.hasNextInt()) {
System.out.println(" \nChoose the existing number");
input.nextLine();
continue;
}
int choice = input.nextInt();
String newClassName, searchClass, newName, addName;
switch (choice) {
case 1:
//Show School List
/*List all class, student, grade and the total grade
in ascending*/
System.out.println("=== SCHOOL LIST ===");
Student[] SortList = studentList1;
//Descending Order Arrays
Comparator<Student> descendingOrder;
descendingOrder = Collections.reverseOrder
(new sortGrade());
Arrays.sort(SortList, descendingOrder);
System.out.println(Arrays.toString(SortList) + "\n");
case 2:
System.exit(0);
break;
default:
System.out.println(" \nChoose the existing number");
}
}
}
}
Java 数组不可调整大小。您不能添加或删除项目。请改用 ArrayList。
如果您绝对不能使用 ArrayList，那么您唯一的其他选择是重新初始化数组，然后将新数组分配给您的原始指针。您可以将此功能封装到如下方法中：
String[] push(String[] array, String push) {
String[] longer = new String[array.length + 1];
for (int i = 0; i < array.length; i++)
longer[i] = array[i];
longer[array.length] = push;
return longer;
}
调用此方法时，您必须将其 return 值分配给原始数组值。这可能有副作用。所以你应该小心它。使用较大的数组可能会很麻烦，因为每次添加内容时都必须对其进行迭代。
我正在创建一个学校系统，它显示所有 class 和学生的列表以及他们的成绩和总成绩**。
但现在我真的卡住了。我可以在列表中显示 class 中的所有数据，但我现在真的不知道该怎么做。请帮助我的代码。
在这段代码中，我使用数组来存储学生，年级，class姓名和class数量的数据。
ARRAYS FOR CLASS AND STUDENT:-
The class can store up to [10 class] but initial it with min 3 class and not more than that max is 10 students can store up to [20 students] and not more than that the max is 20
在此代码中不使用数组列表。
= 我想要的学校列表输出 =
在此输出中，名称按成绩升序排列，并在顶部按数字列出，其中显示 class 的总成绩最高。 用户询问是否返回功能选择
=== SCHOOL LISTS ===
1. Class Thunder with Total grade: 146
2. Class Lightning with Total grade: 103.9
3. Class Sunrise with Total grade: 115.5
--------------------
Class: Sunrise
Class quantity: 5
Student1: James Shawn
Grade: 75
Student2: Ali Pole
Grade: 30.5
Student3: Tong Kim
Grade: 10
Total Grade: 115.5
------------------------
Class: Thunder
Class quantity: 5
Student1: Mark Lee
Grade: 65.5
Student2: James Mic
Grade: 20.4
Student3: James Mic
Grade: 18.0
Total Grade: 103.9
------------------------
Class: Lightning
Class quantity: 5
Student1: Luke Kim
Grade: 90
Student2: Noth Shawn
Grade: 44
Student3: Lex Wale
Grade: 12
Total Grade: 146
Do you want to go back to the selection function?
Press Y or N:
//if yes they will go back to the functionSelection
//if no they will ask users if they want to exit the systems.
Do you want to exit (Y or N):
//if yes they will exit the systems
//if no they will go back to the functionSelection.
我的 JAVA 计划 学生 CLASS:-
import java.util.Comparator;
public class Student {
private String studentName;
private int grade;
public Student(String studentName, int score) {
this.studentName = studentName;
this.grade = grade;
}
public String toString() {
return "\nStudent Name: " + studentName + "\nGrade: " + grade;
}
public String getStudentName() {
return studentName;
}
public int getGrade() {
return grade;
}
public void setStudentName(String studentName) {
this.studentName = studentName;
}
public void setGrade(int grade) {
this.grade = grade;
}
}
//Sorting side
class sortGrade implements Comparator<Student> {
@Override
public int compare(Student a, Student b) {
return (a.getGrade() - b.getGrade());
}
}
CLASS CLASS:-
public class Class {
Student[] student;
private String className;
private int classQuantity;
private int totalGrade = 0;
//add student to the class
public void addNewStudent(String studentName, double grade) {
}
public double calculateTotalGrade() {
for (Student students : student) {
totalGrade += students.getGrade();
}
return Math.round(totalGrade * 10.0) / 10.0;
}
public Class(Student[] student,
String className, int classQuantity) {
this.student = student;
this.className = className;
this.classQuantity = classQuantity;
}
public Class(String className, int classQuantity) {
this.className = className;
this.classQuantity = classQuantity;
}
public String toString() {
String studentList = " ";
for (int i = 0; i < student.length; i++) {
studentList += "\n\tStudent " + (i + 1) + ": " + student[i].getStudentName()
+ "\n\tGrade: " + student[i].getGrade();
}
return "\nClass Name: " + className
+ "\nClass Quantity: " + classQuantity + "\n" + studentList;
}
}
主要驱动程序CLASS:-
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Scanner;
public class MainDriver {
private Object[] a;
void printSort(Student[] sortList) {
for (Object sort : a) {
System.out.print(sort + " ");
}
System.out.println();
}
public static void main(String[] args) {
int size = 10;
Class[] classroom = new Class[size];
Student[] studentList1 = {
new Student("Tong Kim", 10),
new Student("Ali Pole", 30),
new Student("James Shawn", 75)};
Student[] studentList2 = {
new Student("James Mic", 20),
new Student("Ho Kim", 18),
new Student("Mark Lee", 65)};
Student[] studentList3 = {
new Student("Luke Kim", 90),
new Student("Noth Shawn", 44),
new Student("Lex Wale", 12)
};
classroom[0] = new Class(studentList1, "Sunrise", 20);
classroom[1] = new Class(studentList2, "Thunder", 10);
classroom[2] = new Class(studentList3, "Lightning", 5);
Scanner input = new Scanner(System.in);
boolean functionSelection = true;
// Student[] SortList = studentList1;
while (functionSelection) {
System.out.println("=== SCHOOL SYSTEM === \n");
System.out.println("[1] Add New Class");
System.out.println("[2] Exit");
System.out.print("\nChoose a function: ");
//Check if it is other then number
if (!input.hasNextInt()) {
System.out.println(" \nChoose the existing number");
input.nextLine();
continue;
}
int choice = input.nextInt();
String newClassName, searchClass, newName, addName;
switch (choice) {
case 1:
//Show School List
/*List all class, student, grade and the total grade
in ascending*/
System.out.println("=== SCHOOL LIST ===");
Student[] SortList = studentList1;
//Descending Order Arrays
Comparator<Student> descendingOrder;
descendingOrder = Collections.reverseOrder
(new sortGrade());
Arrays.sort(SortList, descendingOrder);
System.out.println(Arrays.toString(SortList) + "\n");
case 2:
System.exit(0);
break;
default:
System.out.println(" \nChoose the existing number");
}
}
}
}
Java 数组不可调整大小。您不能添加或删除项目。请改用 ArrayList。
如果您绝对不能使用 ArrayList，那么您唯一的其他选择是重新初始化数组，然后将新数组分配给您的原始指针。您可以将此功能封装到如下方法中：
String[] push(String[] array, String push) {
String[] longer = new String[array.length + 1];
for (int i = 0; i < array.length; i++)
longer[i] = array[i];
longer[array.length] = push;
return longer;
}
调用此方法时，您必须将其 return 值分配给原始数组值。这可能有副作用。所以你应该小心它。使用较大的数组可能会很麻烦，因为每次添加内容时都必须对其进行迭代。