생성자 (constructor)

public class Student {

	public int studentNumber;
	public String studentName;
	public int grade;
	
	public Student(int studentNumber, String studentName, int grade) {
		this.studentNumber = studentNumber;
		this.studentName = studentName;
		this.grade = grade;
	}
	
	public String showStudentInfo() {
		return studentName + "학생의 학번은 " + studentNumber + "이고, " + grade + "학년 입니다.";
	}
}

ublic class StudentTest {

	public static void main(String[] args) {

		//Student studentLee = new Student();
		
		Student studentLee = new Student(12345, "Lee", 3);
		
		String data = studentLee.showStudentInfo();
		System.out.println(data);
	}

}