Menu Driven Java Program to Sort Student details based on Id, total, Modify name based on id, search based on id, search based on name, add new student, print details of student

import java.util.Scanner;
import java.util.Arrays;

class Student
{
private long id;
private String name;
private int marks[],total;
Student(long tid, String tname,int tmarks[],int ttotal )
{
id=tid;name=tname; marks=tmarks;total=ttotal;
}
public void setName(String tname)
{
name=tname;
}
public String toString()
{
return "regd id = "+ id+" name = "+name + "\n marks in 6 subjects = "+Arrays.toString(marks) +" Total ="+total;
}
public long getId()
{
return id;
}
public String getName()
{
return name;
}
public int[] getMarks()
{
return marks;
}
public int getTotal()
{
return total;
}
}
class SearchSort
{
public static void sortById(Student st[], int n)
{
   
for(int i=0;i<n-1;i++)
      {
for(int j=0;j<n-i-1;j++)
{
if(st[j].getId() > st[j+1].getId())
{
Student temp = st[j];
st[j]=st[j+1];
st[j+1]=temp;
}
}
      }
System.out.println("After sorting based on id, Student details are");
for(int i=0;i<n;i++)
System.out.println(st[i]);
}
public static void sortByTotal(Student st[],int n)
{
for(int i=0;i<n-1;i++)
      {
for(int j=0;j<n-i-1;j++)
{
if(st[j].getTotal() > st[j+1].getTotal())
{
Student temp = st[j];
st[j]=st[j+1];
st[j+1]=temp;
}
}
      }
System.out.println("After sorting based on total, Student details are");
for(int i=0;i<n;i++)
System.out.println(st[i]);
}
public static int linearSearch(Student st[], int n, int key)
{
int flag=0;
for(int i=0;i<n;i++)
{
if(st[i].getId() == key)
return i;
                                    }
return -1;
}
public static int linearSearch(Student st[], int n, String key)
{
int flag=0;
for(int i=0;i<n;i++)
{
if(st[i].getName().equalsIgnoreCase(key))
return i;
                                    }
return -1;
}
}
public class StudentDemo
{
public static void main(String args[])
{
System.out.println(" 1. Add New Student \n 2. Print details of all students  \n 3. Search a student based on id \n 4. Search based on name \n 5. Modify name based on id \n 6. Sort based on id \n 7. Sort based on total \n 8. Exit");
Scanner sc = new Scanner(System.in);
int choice = sc.nextInt();
Student st[] = new Student[100];
int nos=0;
while(true){
switch(choice)
{
case 1:
System.out.println("enter id, name");
int tid=sc.nextInt();
String tname=sc.next();
int tmarks[]=new int[6];
int ttotal=0;
for(int i=0;i<tmarks.length;i++)
{
System.out.println("enter marks of  subject "+i);
tmarks[i]=sc.nextInt();
ttotal=ttotal+tmarks[i];
}
st[nos]  = new Student(tid,tname,tmarks,ttotal);
nos++;
break;
case 2:
for(int i=0;i<nos;i++)
System.out.println(st[i]);
break;
case 3:     System.out.println("enter id to search");
                int key=sc.nextInt();
                int index = SearchSort.linearSearch(st,nos,key);
                if(index == -1)
    System.out.println("search id not found");
               else
    System.out.println("search element found at index " + index +" student details are " +st[index]);
               break;

case 4:
               System.out.println("enter Student name to search");
               String key1=sc.next();
               index = SearchSort.linearSearch(st,nos,key1);
                if(index == -1)
    System.out.println("search id not found");
               else
    System.out.println("search element found at index " + index +" student details are " +st[index]);
               break;
case 5: System.out.println("enter id whose name to be modified");
                int key2=sc.nextInt();
                index = SearchSort.linearSearch(st,nos,key2);
                if(index == -1)
    System.out.println("search id not found");
                else
{
System.out.println("enter Student name ");
st[index].setName(sc.next());
System.out.println(" student details after modifying name = " +st[index]);
}
break;
case 6:
SearchSort.sortById(st,nos);
break;
case 7:
SearchSort.sortByTotal(st,nos);
break;
case 8:
System.exit(0);
}
System.out.println(" 1. Add New Student \n 2. Print details of all students  \n 3. Search a student based on id \n 4. Search based on name \n 5. Modify name based on id \n 6. Sort based on id \n 7. Sort based on total \n 8. Exit");
choice = sc.nextInt();
}
}
}