用Java基础写数组的增删查改

学生类对象

public class Student {
private String id;
private String name;
private int age;
public String getId() {
    return id;
}
public void setId(String id) {
    this.id = id;
}
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}
public int getAge() {
    return age;
}

public void setAge(int age) {
    this.age = age;
}
@Override
        public String toString() {
            return "Student{" +
                    "id='" + id + '\'' +
                    ", name='" + name + '\'' +
                    ", age=" + age +
                    '}';
        }
        public Student(String id, String name, int age) {
            this.id = id;
            this.name = name;
            this.age = age;
        }
    }
}

管理类

//学生管理类
        public class StudengtGl {
            //固定一个班有三十个学生
            Student [] stus=new Student[30];
            //声明一个变量表示当前学生数
            static int count=0;
            /**
             * 添加方法
             */
            public void add(Student stu){
                //将传入过来的学生存为数组
                stus[count]=stu;
                //每添加一个学生当前学生数+1
                count++;
            }
            /**
             * 查询所有方法
             */
            public void queryall(){
                for (int i = 0; i <count ; i++) {
                    System.out.println(stus[i]);
                }
            }
            /**
             * 查询一个,根据传入的ID查询
             */
            public void queryone(String id){
                for (int i = 0; i <count ; i++) {
                    if (stus[i].getId().equals(id)){
                        System.out.println(stus[i]);
                    }
                }
            }
            /**
             * 修改方法，根据id
             */
            public void update(Student stu,String id){
                for (int i = 0; i <count ; i++) {
                    if (stus[i].getId().equals(id)){
                        stus[i]=stu;
                    }
                }

            }
            /**
             * 删除方法根据ID
             */
            public void delete(String id){
                for (int i = 0; i <count ; i++) {
                    if (stus[i].getId().equals(id)){
                        count--;
                        for (int j = i; j <stus.length-1 ; j++) {
                            //从现在要删除的这个开始，后边往前边赋值
                            stus[j]=stus[j+1];
                        }
                    }


                }
            }
            /**
             * main方法，调用
             */
            public static void main(String[] args) {
                StudengtGl sgl=new StudengtGl();
                Student stu=new Student("1","张三",18);
                Student stu2=new Student("2","李四",19);
                Student stu3=new Student("3","王五",20);
                Student stu4=new Student("4","赵六",21);
                sgl.add(stu);
                sgl.add(stu2);
                sgl.add(stu3);
                sgl.add(stu4);
                System.out.println("添加方法后的数组：");
                sgl.queryall();
                System.out.println("查询第二条数据:");
                sgl.queryone("2");
                System.out.println("修改第二条数据后的数组：");
                Student stu22=new Student("22","李四2",192);
                sgl.update(stu22,"2");
                sgl.queryall();
                System.out.println("删除第二条数据后的数组：");
                sgl.delete("22");
                sgl.queryall();
            }

        }


    }
}

本文地址：https://blog.csdn.net/YKYZSYA/article/details/107355225