Student

public class Solution {
    public static class Student {
        private String name;
        private String id;
        private String group;
        private String email;

        Student() {
            this.name = "Student";
            this.id = "000";
            this.group = "K62CB";
            this.email = "uet@vnu.edu.vn";
        }

        Student(String initName, String initID, String initEmail) {
            this.name = initName;
            this.id = initID;
            this.group = "K62CB";
            this.email = initEmail;
        }

        Student(Student s) {
            this.name = s.name;
            this.id = s.id;
            this.group = s.group;
            this.email = s.email;
        }

        Student(String initName, String initID, String initGroup, String initEmail) {
            this.name = initName;
            this.id = initID;
            this.group = initGroup;
            this.email = initEmail;
        }

        public String getName() {
            return this.name;
        }

        public void setName(String nameValue) {
            this.name = nameValue;
        }

        public String getInfo() {
            return this.name + " - " + this.id + " - " + this.group + " - " + this.email;
        }
    }

    public static class StudentManagement {
        private Student[] students;
        private int student_count;

        StudentManagement() {
            this.students = new Student[100];
            student_count = 0;
        }

        public static Boolean sameGroup(Student s1, Student s2) {
            return s1.group == s2.group;
        }

        public void addStudent(Student newStudent) {
            if (this.student_count < 100) {
                students[student_count] = new Student(newStudent.name, newStudent.id, newStudent.group, newStudent.email);
                student_count++;
            }
        }

        public String studentByGroup() {
            Boolean[] checked = new Boolean[student_count];
            for (int i = 0; i < student_count; i++)
                checked[i] = false;
        }

        public void removeStudent(String findid) {
            int index = 0;
            for (int i = 0; i < student_count; i++)
                if (this.students[i].id == findid) {
                    for (int k = 0; i < student_count; i++)
                        students[i] = students[i + 1];
                    student_count--;
                }
        }
    }

    public static void main(String[] args) {
        Student studentAn = new Student("Nguyen Van An", "17020001", "k62CC", "17020001@vnu.edu.vn");
        int[] a = new int[100];
    }
}