Student Management System (Basic Version)
Table of Content:
Objective:
To practice Java class & object concepts (attributes, methods, constructors) along with basic operations like input/output, arrays, and simple logic.
Requirements:
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Create a class
Studentwith the following:-
Attributes:
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studentId(int) -
name(String) -
age(int) -
grade(String)
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Constructor to initialize these values.
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Method
displayInfo()→ prints student details. -
Method
updateGrade(String newGrade)→ updates the grade.
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Create a class
StudentManagementthat will:-
Store multiple students in an array or ArrayList.
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Have methods:
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addStudent(Student s)→ add new student. -
showAllStudents()→ display all student info. -
findStudentById(int id)→ search a student.
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-
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In the
mainmethod:-
Create at least 3 student objects.
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Add them into the management system.
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Display all students.
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Update a student’s grade.
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Search for a student by ID and display result.
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Solutions
import java.util.ArrayList; import java.util.Scanner; // Class representing a Student class Student { int studentId; String name; int age; String grade; // Constructor Student(int studentId, String name, int age, String grade) { this.studentId = studentId; this.name = name; this.age = age; this.grade = grade; } // Method to display student info void displayInfo() { System.out.println("ID: " + studentId + " | Name: " + name + " | Age: " + age + " | Grade: " + grade); } // Method to update grade void updateGrade(String newGrade) { this.grade = newGrade; System.out.println(name + "'s grade updated to " + newGrade); } } // Class for managing multiple students class StudentManagement { ArrayList students = new ArrayList<>(); // Add a new student void addStudent(Student s) { students.add(s); System.out.println("Student Added: " + s.studentId + ", " + s.name); } // Show all students void showAllStudents() { System.out.println("\n--- Showing All Students ---"); for (Student s : students) { s.displayInfo(); } } // Find student by ID Student findStudentById(int id) { for (Student s : students) { if (s.studentId == id) { return s; } } return null; // Not found } } // Main class public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); StudentManagement sm = new StudentManagement(); // Adding some students sm.addStudent(new Student(101, "Riya", 20, "A")); sm.addStudent(new Student(102, "Arjun", 21, "B")); sm.addStudent(new Student(103, "Sneha", 19, "C")); // Show all students sm.showAllStudents(); // Update a grade Student student = sm.findStudentById(102); if (student != null) { student.updateGrade("A"); } // Search for a student by ID System.out.print("\nEnter Student ID to search: "); int searchId = sc.nextInt(); Student found = sm.findStudentById(searchId); if (found != null) { System.out.println("Found Student:"); found.displayInfo(); } else { System.out.println("Student with ID " + searchId + " not found!"); } sc.close(); } }
Output:
Student Added: 101, Riya Student Added: 102, Arjun Student Added: 103, Sneha --- Showing All Students --- ID: 101 | Name: Riya | Age: 20 | Grade: A ID: 102 | Name: Arjun | Age: 21 | Grade: B ID: 103 | Name: Sneha | Age: 19 | Grade: C Arjun's grade updated to A Enter Student ID to search: 102 Found Student: ID: 102 | Name: Arjun | Age: 21 | Grade: A
import java.util.Scanner; // Class representing a Student class Student { int studentId; String name; int age; String grade; // Constructor Student(int studentId, String name, int age, String grade) { this.studentId = studentId; this.name = name; this.age = age; this.grade = grade; } // Method to display student info void displayInfo() { System.out.println("ID: " + studentId + " | Name: " + name + " | Age: " + age + " | Grade: " + grade); } // Method to update grade void updateGrade(String newGrade) { this.grade = newGrade; System.out.println(name + "'s grade updated to " + newGrade); } } // Class for managing multiple students using a fixed-size array class StudentManagement { Student[] students; int count; // keeps track of current number of students // Constructor with a maximum number of students StudentManagement(int maxStudents) { students = new Student[maxStudents]; count = 0; } // Add a new student void addStudent(Student s) { if (count < students.length) { students[count] = s; count++; System.out.println("Student Added: " + s.studentId + ", " + s.name); } else { System.out.println("Cannot add more students. Array is full!"); } } // Show all students void showAllStudents() { System.out.println("\n--- Showing All Students ---"); for (int i = 0; i < count; i++) { students[i].displayInfo(); } } // Find student by ID Student findStudentById(int id) { for (int i = 0; i < count; i++) { if (students[i].studentId == id) { return students[i]; } } return null; // Not found } } // Main class public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); StudentManagement sm = new StudentManagement(10); // max 10 students // Adding some students sm.addStudent(new Student(101, "Riya", 20, "A")); sm.addStudent(new Student(102, "Arjun", 21, "B")); sm.addStudent(new Student(103, "Sneha", 19, "C")); // Show all students sm.showAllStudents(); // Update a grade Student student = sm.findStudentById(102); if (student != null) { student.updateGrade("A"); } // Search for a student by ID System.out.print("\nEnter Student ID to search: "); int searchId = sc.nextInt(); Student found = sm.findStudentById(searchId); if (found != null) { System.out.println("Found Student:"); found.displayInfo(); } else { System.out.println("Student with ID " + searchId + " not found!"); } sc.close(); } }
import java.util.Scanner; public class Student { // Attributes int studentId; String name; int age; String grade; // Constructor Student(int studentId, String name, int age, String grade) { this.studentId = studentId; this.name = name; this.age = age; this.grade = grade; } // Display student info void displayInfo() { System.out.println("ID: " + studentId + " | Name: " + name + " | Age: " + age + " | Grade: " + grade); } // Update grade void updateGrade(String newGrade) { this.grade = newGrade; System.out.println(name + "'s grade updated to " + newGrade); } // --- Static array and management methods inside the same class --- static Student[] students = new Student[10]; static int count = 0; // Add a student static void addStudent(Student s) { if (count < students.length) { students[count] = s; count++; System.out.println("Student Added: " + s.studentId + ", " + s.name); } else { System.out.println("Cannot add more students. Array is full!"); } } // Show all students static void showAllStudents() { System.out.println("\n--- Showing All Students ---"); for (int i = 0; i < count; i++) { students[i].displayInfo(); } } // Find student by ID static Student findStudentById(int id) { for (int i = 0; i < count; i++) { if (students[i].studentId == id) { return students[i]; } } return null; } // Main method public static void main(String[] args) { Scanner sc = new Scanner(System.in); // Adding students addStudent(new Student(101, "Riya", 20, "A")); addStudent(new Student(102, "Arjun", 21, "B")); addStudent(new Student(103, "Sneha", 19, "C")); // Show all students showAllStudents(); // Update a grade Student student = findStudentById(102); if (student != null) { student.updateGrade("A"); } // Search for a student by ID System.out.print("\nEnter Student ID to search: "); int searchId = sc.nextInt(); Student found = findStudentById(searchId); if (found != null) { System.out.println("Found Student:"); found.displayInfo(); } else { System.out.println("Student with ID " + searchId + " not found!"); } sc.close(); } }