Write a menu-driven program that creates a data file containing a list of phone numbers in the following form John 23456 Ahmed 9876 ……….. ……… Use a class object to store each set of data, access the created file and implement the following tasks I. Find a phone number designated persons II. Specify the name if the phone number is known III. Update the phone number whenever there is a change.

Write a menu driven program that will create a data file containing the list of telephone numbers in the following form John 23456 Ahmed 9876 …… Use a class object to store each set of data, access the file created and implement the following tasks.
I. Determine the telephone number of specified person
II. Determine the name if telephone number is known
III. Update the telephone number, whenever there is a change.

include
#include
#include

OUTPUT FOR THE PROGRAM

#include

using namespace std;

class person
{
   public:
    char name[10];
    int phno;
   
    void input_data()
    {
      cout<<"\n Enter Name:-";
      cin>>name;
      cout<<"\n Enter Phone no:-";
      cin>>phno;
        }
   
    void put_data()
    {
      cout<        }
 };


int main()
{
    person rec;
    int phone,pos,choice,offset,i;
    fstream fp;
    ifstream in;
    ofstream out;
    char nm[20];
    char ans='y';
 
    do
    {
      cout<<"\n Main Menu ";
      cout<<"\n 1. Read File ";
      cout<<"\n 2. Write File ";
      cout<<"\n 3. Determine Name if Telephone number is specified ";
      cout<<"\n 4. Determine Telephone number if Name is specified ";
      cout<<"\n 5. Update Telephone no.";
      cout<<"\n Enter ur choice: ";
      cin>>choice;

    switch(choice)
    {
      case 1:
        in.open("Home:\\test.txt",ios::in);
cout<<"\nThe contents of file are....\n";
        while(in.read((char*)&rec,sizeof(rec)))
        {
          rec.put_data();
            }
        in.close();
        break;

        case 2:
        rec.input_data();
          out.open("Home:\\test.txt",ios::out|ios::app|ios::binary);
        out.write((char*)&rec,sizeof(rec));
        out.close();
        break;
   
      case 3:
        cout<<"\n Enter the phone no.";
        cin>>phone;
        fp.open("Home:\\test.txt",ios::ate|ios::in|ios::out|ios::binary);
        fp.seekg(0,ios::beg);
        pos=-1;
        i=0;
       

        while(fp.read((char*)&rec,sizeof(rec)))
        {
          if(phone==rec.phno)
          {
            pos=i;
            break;
            }
            i++;
          }
        offset=pos*sizeof(rec);
        fp.seekp(offset);          //seeking the desired record for Deletion
        fp.read((char*)&rec,sizeof(rec));
        cout<<"\n Name: "<        fp.close();
        break;

      case 4:
        cout<<"\n Enter the Name:";
        cin>>nm;
        fp.open("Home:\\test.txt",ios::ate|ios::in|ios::out|ios::binary);
        fp.seekg(0,ios::beg);
      pos=-1;
        i=0;
        while(fp.read((char*)&rec,sizeof(rec)))
        {
          if((strcmp(nm,rec.name))==0)
            {
              pos=i;
              break;
            }
          i++;
          }   
    offset=pos*sizeof(rec);
    fp.seekp(offset);    //Seeking the desired record for deletion
    fp.read((char*)&rec,sizeof(rec));
    cout<<"\n Telephone Number: "<    fp.close();
    break;

      case 5:
        cout<<"\n Enter the name: ";
        cin>>nm;
        fp.open("Home:\\test.txt",ios::ate|ios::in|ios::out|ios::binary);
        fp.seekg(0,ios::beg);
        pos=-1;
        i=0;
     
          while(fp.read((char*)&rec,sizeof(rec)))
          {
              if((strcmp(nm,rec.name))==0)
                {
                  pos=i;
                  break;
}
                   
                i++;
                }
      offset=(pos)*sizeof(rec);
      fp.seekp(offset);
      cout<<"\n Current Phone: "<      cout<<"\n Enter new Telephone no.: ";
      cin>>phone;
      rec.phno = phone;
      fp.write((char*)&rec,sizeof(rec))<      cout<<"\n Record updated!!!\n";
      fp.seekg(0);
     

      while(fp.read((char*)&rec,sizeof(rec)))
        {
            rec.put_data();
        }
        fp.close();
        break;
}
cout<<"\n Do u want to continue?(y/n)";
      cin>>ans;
    }while(ans=='y');
return 0;
}


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