Question

im taking java102

can someone help with this ?

call it (Student Version 2)

Write another version of class Student that has a firstName,
lastName, id, mobilePhone and a count. Declare the count as a static
variable. The count is incremented every time an object of this class is
created. Write the default constructor, a constructor that takes
parameters: firstName, lastName, id and mobilePhone. Write a third
constructor that takes only firstName and lastName. Write the set
and get methods for your attributes. Make sure that the phone
number consists of 10 numbers and that the first name and last name
consist of more than 2 characters. Create a function that displays all
the student information and another that displays only the name.

Then write a demo program that tests the methods of your Student
class.

Answer 1

#source code:

import java.util.*;
import java.lang.*;
class Student{
   String firstname;
   String lastname;
   String phonenumber;
   int id;
   static int count=0;
  
   Student(){
       /*default constructor*/
  
      
   }
   Student(String fname,String lname,int id,String pnumber){
       count++;
       this.firstname=fname;
       this.lastname=lname;
       this.id=id;
       this.phonenumber=pnumber;
       if(this.firstname.length()<=2 || this.lastname.length()<=2 || this.phonenumber.length()<10 || this.phonenumber.length()>10){
           System.out.println("name lessthan 2 characters or phone number error");
       }
       else{
           display_information();
          
       }
      
   }
   Student(String fname,String lname){
       count++;
       display_names(fname,lname);
      
   }
  
   void display_information(){
       System.out.println("firstname:"+firstname+" lastname:"+lastname+" id:"+id+" phonenumber:"+phonenumber);
   }
   void display_names(String firstname,String lastname){
       System.out.println("names:"+firstname+" "+lastname);
   }
   public static void main(String args[]){
       Student s1=new Student("vishnu","namana",14,"9703850705");
       Student s2=new Student("vishnu","namana");
       Student s3=new Student("v","namana",15,"9709850705");
       Student s4=new Student("v","namana");
       Student s5=new Student("red","namana",14,"970850705");
       Student s6=new Student("red","namana");
       System.out.println("object is created:"+Student.count);

   }
}

#output:

#if you have any doubt comment below.....