源于chatGPT仅供参考
```java
import java.util.*;
class Student {
private String studentNumber;
private String name;
private String gender;
public Student(String studentNumber, String name, String gender) {
this.studentNumber = studentNumber;
this.name = name;
this.gender = gender;
}
public String getStudentNumber() {
return studentNumber;
}
public String getName() {
return name;
}
public String getGender() {
return gender;
}
}
public class Main {
public static void main(String[] args) {
// 创建List对象,并添加10个学生的信息到List中
List<Student> studentList = new ArrayList<>();
studentList.add(new Student("001", "Alice", "Female"));
studentList.add(new Student("002", "Bob", "Male"));
studentList.add(new Student("003", "Charlie", "Male"));
studentList.add(new Student("004", "David", "Male"));
studentList.add(new Student("005", "Eva", "Female"));
studentList.add(new Student("006", "Frank", "Male"));
studentList.add(new Student("007", "Grace", "Female"));
studentList.add(new Student("008", "Henry", "Male"));
studentList.add(new Student("009", "Ivy", "Female"));
studentList.add(new Student("010", "Jack", "Male"));
// 遍历该List并输出
for (Student student : studentList) {
System.out.println("Student Number: " + student.getStudentNumber());
System.out.println("Name: " + student.getName());
System.out.println("Gender: " + student.getGender());
System.out.println("-----------------------");
}
// 调用相关方法实现对该List的CRUD操作
Student newStudent = new Student("011", "Kelly", "Female");
// i. 将对象E 添加至List的末尾处
studentList.add(newStudent);
// ii. 将对象E 添加至List的指定索引处
studentList.add(5, newStudent);
// iii. 移除List指定索引处的元素
studentList.remove(3);
// iv. 查找指定元素
Student foundStudent = null;
for (Student student : studentList) {
if (student.getName().equals("Bob")) {
foundStudent = student;
break;
}
}
System.out.println("Found Student: " + foundStudent.getName());
// 对List进行排序并输出
Collections.sort(studentList, Comparator.comparing(Student::getName));
System.out.println("Sorted List:");
for (Student student : studentList) {
System.out.println("Name: " + student.getName());
}
// 将List转换为数组
Student[] studentArray = studentList.toArray(new Student[0]);
System.out.println("Converted Array:");
for (Student student : studentArray) {
System.out.println("Name: " + student.getName());
}
}
}
以上是用Java实现的代码,其中:
Student
类,包含学号、姓名和性别等信息,并编写了一个构造方法。Main
类中创建了一个ArrayList
对象,并添加了10个学生的信息到该List中。```
向ArrayList类的对象中存储基本数据类型,必须使用基本数据类型对应的包装类。写成以下方式错误:
ArrayList<int> arrayA = new ArrayList<>();
泛型不能直接写成int,long,float等,需写成包装类。包装类是引用类型,在java.lang包中有。
不同基本数据类型与包装类型的对应关系如下:
基本类型 | 包装类型 |
---|---|
byte | Byte |
short | Short |
int | Integer |
long | Long |
float | Float |
double | Double |
char | Character |
boolean | Boolean |
这里需要特别注意int 和char 的包装类型,分别是Integer 和Character,其他首字母大即可
代码示例:
import java.util.ArrayList;
public class ArrayTestTest {
public static void main(String[] args) {
ArrayList<Integer> listA = new ArrayList<>();
listA.add(100);
listA.add(200);
listA.add(300);
System.out.println(listA);
System.out.println(listA.get(1));
}
}
输出结果如下: