CBSE Class 12 Computer Science 1 Marks HOTs

1 Mark Questions

Programming in C++

1. Observe the program segment carefully and answer the question that follows:
class item
{
int item_no;
char item_name[20];
public:
void enterDetail( );
void showDetail( );
int getItem_no( ){ return item_no;}
};
void modify(item x, int y )
{
fstream File;
File.open( “item.dat”, ios::binary | ios::in | ios::out) ;
item i;
int recordsRead = 0, found = 0;
while(!found && File.read((char*) &i , sizeof (i)))
{
recordsRead++;
if(i . getItem_no( ) = = y )
{
_________________________//Missing statement
File.write((char*) &x , sizeof (x));
found = 1;
}
}
if(! found)
cout<<”Record for modification does not exist” ;
File.close() ;
}

If the function modify( ) is supposed to modify a record in the file “ item.dat “, which item_no is y, with the values of item x passed as argument, write the appropriate
statement for the missing statement using seekp( ) or seekg( ), whichever is needed, in the above code that would write the modified record at its proper place.

2. Observe the program segment carefully and answer the question that follows:
class member
{
int member_no;
char member_name[20];
public:
void enterDetail( );
void showDetail( );
int getMember_no( ){ return member_no;}
};
void update(member NEW )
{
fstream File;
File.open( “member.dat”, ios::binary|ios::in|ios::out) ;
member i;
while(File .read((char*) & i , sizeof (i)))
{
if(NEW . getMember_no( ) = = i . getMember_no( ))
{
_________________________//Missing statement
File.write((char*) &NEW , sizeof (NEW));
}
}
File.close() ;
}
If the function update( ) is supposed to modify the member_name field of a record in the file “ member.dat” with the values of member NEW passed as argument, write the
appropriate statement for the missing statement using seekp( ) or seekg( ), whichever is needed, in the above code that would write the modified record at its proper place.

3. Observe the program segment carefully and answer the question that follows:
class item
{
int item_no;
char item_name[20];
public:
void enterDetails( );
void showDetail( );
int getItem_no( ){ return item_no;}
};
void modify(item x )
{
fstream File;
File.open( “item.dat”, _______________ ) ; //parameter missing
item i;
while(File .read((char*) & i , sizeof (i)))
{
if(x . getItem_no( ) = = i . getItem_no( ))
{
File.seekp(File.tellg( ) – sizeof(i));
File.write((char*) &x , sizeof (x));
}
else
File.write((char*) &i , sizeof (i));
}
File.close() ;
}

If the function modify( ) modifies a record in the file “ item.dat “ with the values of item x passed as argument, write the appropriate parameter for the missing parameter in
the above code, so as to modify record at its proper place.

4. Observe the program segment carefully and answer the question that follows:
class member
{
int member_no;
char member_name[20];
public:
void enterDetails( );
void showDetail( );
int getMember_no( ){ return member_no;}
};
void update(member NEW )
{
fstream File;
File.open( “member.dat”, ios::binary|ios::in|ios::out) ;
member i;
while(File .read((char*) & i , sizeof (i)))
{
if(NEW . getMember_no( ) = = i . getMember_no( ))
{
File.seekp( _________ , ios::cur ) //Paremeter Missing
File.write((char*) &NEW , sizeof (NEW));
}
}
File.close() ;
}
If the function update( ) is supposed to modify a record in the file “ member.dat” with the values of member NEW passed as argument, write the appropriate parameter for the
missing parameter in the above code, so as to modify record at its proper place.

5. A file named as “STUDENT.DAT” contains the student records, i.e. objects of class student.
Write the command to open the file to update a student record. (Use suitable stream class and file mode(s).

6. A file named as “STUDENT.DAT” contains the student records, i.e. objects of class student.
Assuming that the file is just opened through the object FILE of fstream class, in the required file mode, write the command to position the put pointer to point to second record from the last record.

7. A file named as “STUDENT.DAT” contains the student records, i.e. objects of class student.
Assuming that the file is just opened through the object FILE of fstream class, in the required file mode, write the command to position the get pointer to point to fifth record from the beginning.

8. Read the code given below and answer the question:
void main( )
{
char ch = ‘A’;
fstream outFile (“data.dat”, ios::out);
outFile<<ch<<ch;
}
If the file contains GOOD before execution, what will be the contents of the file after execution of this code?

9. Observe the program segment carefully and answer the question that follows:
class student
{
int student_no;
char student_name[20];
int mark;
public:
void enterDetail( );
void showDetail( );
void change_mark( ); //Function to change the mark
int getStudent_no( ){ return student_no;}
};
void modify( int y )
{
fstream File;
File.open( “student.dat”, ios::binary|ios::in|ios::out) ;
student i;
int recordsRead = 0, found = 0;
while(!found && File .read((char*) & i , sizeof (i)))
{
recordsRead++;
if(i . getStudent_no( ) = = y )
{
i . change_mark( );
_________________________//Missing statement 1
_________________________//Missing statement 2
found = 1;
}
}
if( found = = 1)
cout<<”Record modified” ;
File.close() ;

}
If the function modify( ) is supposed to change the mark of a student having student_no y in the file “student.dat”, write the missing statements to modify the student record.

10. Observe the program segment carefully and answer the question that follows:
class item
{
int item_no;
char item_name[20];
public:
void enterDetail( );
void showDetail( );
int getItem_no( ){ return item_no;}
};
void modify(item x )
{
fstream File;
File.open( “item.dat”, ios::binary|ios::in|ios::out ) ;
item i;
while(File .read((char*) & i , sizeof (i)))//Statement 1
{
if(x . getItem_no( ) = = i . getItem_no( ))
{
File.seekp(File.tellg( ) – sizeof(i));
File.write((char*) &x , sizeof (x));
}
}
File.close() ;
}
If the function modify( ) modifies a record in the file “ item.dat” with the values of item x passed as argument, rewrite statement 1 in the above code using ios::eof( ) , so as to modify record at its proper place.

2 Marks Questions

Programming in C++

1. What is wrong with the following while loop:
a. int counter = 1; b. int counter = 1;
while ( counter < 100) while ( counter < 100)
{ cout << counter << “\n;
cout << counter << “\n; counter + +;
counter - -;
}

2. What will be the output of following:
void main ( )
{
int val = 10;
cout << val ++ << val << ++ val;
}