CHAPTER 1: Review of C++
1. What
are tokens, identifiers, literals. Pl learn the naming conventions of these.
·
Tokens- Smallest individual unit. Following are
the tokens
·
Keyword-Reserve word having special meaning the
language and can’t be used as
o
identifier.
·
Identifiers-Names given to any variable, function,
class, union etc. Naming convention (rule) for writing identifier is as under:
o
First
letter of identifier is always alphabet.
o
Reserve
word cannot be taken as identifier name.
o
No
special character in the name of identifier except under score sign ‘_’.
·
Literals-Value of specific data type assign to a
variable or constant. Four type of Literals: i) Integer Literal i.e int
x =10 ii) Floating point
Literal i.e float x=123.45
§
iii)Character
Literal i.e char x= ‘a’, enclosed in single quotes and
single character only. iv)
String Literal i.e
cout<< “Welcome” , anything enclosed in double quotes
·
Operator – performs some action on data o Arithmetic(+,-,*,/,%) o Assignment operator (=) o Increment
/ Decrement (++, --) o Relational/comparison
(<,>,<=,>=,==,!=). o Logical(AND(&&),OR(||),NOT(!).
o
Conditional
(? :)
2. Name
simple, compound and user defined data types.
·
Fundamental
type/simple : Which are not composed any other data type
i.e. int, char, float and void
·
Derived
data type /compound: Which are made up of fundamental data type
i.e array, function, class etc
·
User
defined: they are tailor
made data types created by the user eg structures and classes
3. What
are macros? How they are implemented in C++?
Macros: These are very simple inline functions which are written
before main().These are on line functions returning very simple calculations eg
area of square circle etc.When the compiler encounter a function call the
function call is replaced by the program code. This ensures faster processing
by removing the overhead required for transferring control to function
definition.
eg
#include
<iostream.h>
#define
area_square(s) s*s
void main()
{
cout<<"Area of square: "<<area_square(4);
}
output:
Area of
square: 16
4. What
is typedef? How to define another name for string, int, float or char
datatypes?
Used to define new data type name.
e.g. typedef char Str80[80];
Str80 str;
So the new
name for char data type here will be Str80. str is a variable of Str80
having size as 80 char.
eg 2. typedef
int age;
age x;
Here Age is
the new name for int data type . x is a variable having age data type.
5. How
can you call a variable by two names?
By
using alias name as in reference variables. Eg When we pass a variable by
reference in a function, the same variable has two names, one in the calling
function and the other in the function definition.
Eg
void func1( int & marks)
{
if(marks>90) alias
name
cout<<”V.Good”;
else
Cout<<”Good”;
}
void
main()
{
int m;
cout<<”Enter
marks”;
cin>> m;
func1(m);
} actual name
6. What
are reference variables?
7. References:
A reference
is an alternative name for an object or variable A reference variable provides
an alias for a previously defined variable. A reference declaration consists of
base type , an & (ampersand), a reference variable name equated to a
variable name .the general syntax form of declaring a reference variable is as
follows.
Type &
ref_variable = variable_name;
Where
type is any valid C++ datatype, ref_variable is the name of reference
variable that will point to variable denoted by variable_name.
e.g int a=
10;
int
&b= a;
then the
value of a is 10 and the value of b is also 10;
8. Diff
between ‘’h’’ & ‘h’
Here
“h” is a string having size 2 bytes. ‘h’ is a character constant with size 1
byute.
9. Diff
between getch ( ) & getche( )
getch()
and getche() both accept a single character from inout stream, getche also
shows the character on the screen( e stands for echo).
10. Diff
between toupper( ) & isupper( )
toupper()-converts
given character to uppercase
isupper()-
returns true if the character is uppercase else returns false.
11. Diff
between if (i=2) & if(i= =2)
(i=2)
: this assigns value 2 to i
if(i= =2): this checks whether the value of I
is 2 or not and returns true or false accordingly.
12. use
of # include
#include is
the preprocessor directive used in C++ programs. This statement tells the
compiler to
include the specified file into the program. This line is compiled by the
processor
before the
compilation of the program.
e.g
#include<iostream.h>
the above
line include the header file iostream into the program for the smooth running
of the
program.
13. What is typecasting?
Type
Casting
Explicit
type casting operator
Type casting
operators allow you to convert the data type of a given variable to
another. There are
several ways
to do this
1.To precede
the expression to be converted by the new type enclosed between
parentheses ( ) :
int i;
float f
=3.14;
i = ( int )
f;
The previous
code converts the float number 3.14 to an integer value (3), the remainder is
lost. Here,
the
typecasting operator was (int).
2. Another
way to do the same thing in C++ is using the functional notation: preceding the
expression to be converted by the type and enclosing the expression between
parentheses:
i = int
(f );
Both ways of
type casting are valid in C++.
14. Compilation and Linking
Compilation
refers to the processing of source code files (.c, .cc, or .cpp) and the
creation of
an 'object'
file. This step doesn't create anything the user can actually run. Instead, the
compiler
merely produces the machine language instructions that correspond to the source
code file
that was compiled. For instance, if you compile (but don't link) three separate
files,
you will have
three object files created as output, each with the name <filename>.o or
<filename>.obj
(the extension will depend on your compiler). Each of these files contains a
translation
of your source code file into a machine language file -- but you can't run them
yet!
You need to
turn them into executables your operating system can use. That's where the
linker comes
in.
Linking
refers to the creation of a single executable file from multiple object files.
In this step,
it is common
that the linker will complain about undefined functions (commonly, main itself).
During
compilation, if the compiler could not find the definition for a particular
function, it
would just
assume that the function was defined in another file. If this isn't the case,
there's no
way the
compiler would know -- it doesn't look at the contents of more than one file at
a time.
The linker,
on the other hand, may look at multiple files and try to find references for
the
functions
that weren't mentioned.
15. Diff
between local(automatic) & global variables.
The
lifetime and scope of local variables is the function or block in which they
are declared.
The
lifetime and scope of global variables is the program in which they are
declared.
16. How
many cases are possible in a select case?
256,
range of char.
17. What
is difference between actual and formal parameters?
Actual Parameters
Variables
associated with function name during function call statement.
Formal Parameters
Variables
which contains copy of actual parameters inside the function definition.
18. What
do you mean by entry controlled and exit controlled loop?
19. Entry control loop works for true condition and preferred
for fixed no.of times.eg for, while
20. Exit Control Loop execute at least once if the
condition is false at beginning.eg do while
21. Difference
between signed and unsigned.
The
range of signed data type is lower than unsigned as one byte is reserved to
store the sign(-, +)
Eg
For char datatype.
1byte
signed: -128 to 127
unsigned: 0 to 255
22. What
do you understand by .h in header file declarations?
23. .h
stands for header files, an extension given to these types of files.
24. Why
do we use comments? Declare a single line comment and a multi line comment.
COMMENTS
in a C++ program.:
Comments are
the line that compiler ignores to compile or execute. There are two types of
comments
in C++.
1. Single
line comment: This type of comment deactivates only that line where comment is
applied.
Single line comments are applied with the help of “ //” .
e.g //
cout<<tomorrow is holiday
the above
line is proceeding with // so compiler wont access this line.
2. Multi line
Comment: This Type of comment deactivates group of lines when applied. This
type of
comments are
applied with the help of the operators “/*” and “*/ ”. These comment mark with
/*
and end up
with */. This means everything that falls between /*and */ is considered even
though it
is spread
across many lines.
e.g
#include<iostream.h>
int
main ()
{
cout<<
“ hello world”;
/* this is
the program to print hello world
For
demonstration of comments */
}
In the above
program the statements between /* and */ will be ignored by the compiler.
25. Why
do we use iostream.h?
To
be able to connect the program to the input and output stream.
26. What
is the difference between gets() and getline()?
27. What
type of function is main()- user defined or in-built?
in-built
28. What
happens during running
During
running .exe and .bak files are created and the program is loaded in the ram.
29. Diff.
between continue & break & exit
exit()- defined in process.h and used to terminate the program
depending upon certain condition.
break- exit from the current loop depending upon certain condition.
continue- to skip the remaining statements of the
current loop and passes control to the next loop control statement.
30. What
are default arguments?
CHAPTER 2 OBJECT ORIENTED
PROGRAMMING
Concepts
of oops
Diff. between procedural programming and object oriented
programming.
CHAPTER 3 CLASSES AND OBJECTS
Passing object through functions
Declaration& implementation of class, Diff between class
& structure
Difference between object array and ordinary array?
CHAPTER 4 CONSTRUCTORS AND
DESTRUCTOR
What will happen if we declare a constructor/ destructor in
the private section of a class?
Can we have a parameterized/ copy constructor in a class
without having a default constructor?
Implicit call and explicit call of constructors.
Uses of copy constructor
Uses of constructors& destructors & definition
How is a constructor different from a simple function?
Types of constructors
Constructor overloading
What is the concept of polymorphism? How is it implemented
in C++?
CHAPTER 5 INHERITENCE
Various visibility modes in inheritance
Uses
of function overloading and inheritance.
Name and elaborate on the types of Inheritance.
What do you understand by transitive nature in inheritance?
CHAPTER 6 DATA STRUCTURES
What are
data structures?
Different
types of data structures
CHAPTER 7 ARRAYS
Diff. B/W binary & linear search. Which one is better?
Array’s of structure are one dimensional & two
dimensional
Diff between insertion , selection and bubble sort
How many bytes of data will be stored in each of the
following :
a. char
a[10];
b. int a1[10];
Difference between array and structures.
CHAPTER 8 STACKS AND QUEUES
Application of stacks & queues
Application of postfix expressions
What do you mean by Overflow and Underflow in
the context of stacks?
CHAPTER 9 POINTERS
Difference between stack as an array and stack as a linked
list.
Uses of pointers.
What is dynamic data structures ?
What is A in char
A[10]
How can we declare dynamic arrays?
Consider the declaration : char *s[20] :- is it a 1-D or 2-D
array ? Why?
What do you understand by static and dynamic memory? Give
examples.
CHAPTER 11 FILE HANDLING
Differentiate between read and write function and explain
them in detail.
Definition of file & stream
Diff between files and linked list
Diff between files & arrays
How are records implemented in C++?
Diff between binary & text files
Which is base class fstream
/ iostream
Difference between linked list and files.
Diff between file & array
Writing/Reading characters to/from file
Writing/Reading strings to/from file
Diff between text & binary file
Writing/Reading objects
to/from file
Add / modifying / delete from a file
CHAPTER 12 MY SQL
What is DDL and DML?
76. Can we insert a new column into a table?
77. Can we delete a column from a table?
78. Can we delete a row from a table?
79. Can we insert a new row into a table?
I have item .dbf
having fields item no. & category. Give command to count the total
number of items in each category
61. Student by
having fields Roll no., Class, Section count total number of students in each section of class XII. How can we make
changes in one particular column of a table
59. Diff between
database & table
- What
happens when the drop table command is executed?
- Explain
all the cases of the like operator in SQL.
- In
SQL can MAX function be applied to date and char type date
GENERAL C++ VIVA QUESTIONS
1. PROJECT VIVA
a. Be
thorough in your project. b. Logic used (in terms of storing data / reading
text files / manipulation of data) c. For application based projects
• Adding
Records
•
Modification
• Deletion
• Search
on fields Binary file operations. d. Working of Project
In the first category i.e. “about project title” the few questions
are: a) What is the significance of this title? b) Why you choose this title?
c) Are you think that this title is suitable for Class XII ? d) Can you give
any other title to your project work? e) Can you explain your title of the
project in 100 words? h) What does your project do? i) How much time you taken
in Analysis, Coding and Testing k) What are the uses of the project?
2. C++ Concepts (Differences)
A. Fundamental Data Types Derived Data
Types
• Basic
Data Type • Derived from Basic Data types
•
Int,char,void, float,double • Array,struct,class
B. Struct Class
• Members
are Public by default Members are Private by default
C. Dynamic Memory Allocation Static Memory
Allocation
•
Allocated during Run Time using new operator
Allocated
during compile time and fixed
• Memory
can be deallocated during run time.
Memory can
only be deallocated when scope gets over.
D.Call by Reference Call By value
• Value
gets reflected at original location.
Value
remains unchanged.
E. Global Variables Local Variables
Variables
defined above all function definitions
Variables
defined within a block or a function.
F. #define Macro Function Code gets substituted at place of
function call.
Memory
control is transferred at the place of function defined.
G= Assignment Operator = = Comparison
Operator
Assigns a
value to the variable. Compares the values and return 1 or 0.
H.Logical Operators Relational Operators
! Not,
&& AND, || OR < ,>, == , !=,>=,<=
I.Compile Time Errors Run Time Errors
Syntax
errors occurs at compile time. Logical Errors occurs at Run Time
J.Member Functions Non member Functions
➢
Defined/Declared inside the class ➢ Defined Outside the class
➢ Public Member
Functions are
accessed
by object of that class
➢ Functions are
called by their name
and object
can passed as parameters.
K.Break Continue
➢ Takes the
control out of the loop Takes the control back to next iteration.
LSwitch Case If..else
➢ Only used with
char / int ➢ Only used for
equality comparison
➢ Can be used
with all data types ➢ Mix
expressions can be evaluated.
M.Text Files Binary Files
➢ Data in ASCII
format ➢ Not Secure and
contains plain text
➢ Data in Binary
form ➢ Data stored in
blocks of object size.
N. File Pointer Position Opening Mode
Beginning
Ios::in, ios::out, ios::app
End
Ios::ate
O. Seeekg/Seekp Tellg/tellp
Place the
file pointer at desired position Tells the current position of pointer
P. Statement Placement of file pointer
➢ f.seekg(0);
Beginning
➢ f.seekg(40);
40 bytes ahead from beginning
➢
f.seekg(0,ios::end) End of file
➢
f.seekg(-10,ios::cur) 10 bytes back from current position.
Q. Stack Queue
➢ LIFO Manner ➢ FIFO Manner
➢ Only one end –
Top ➢ Front –
Deletion
➢ Rear -
Insertion
R. Constructor Destructor
➢ Automatically
called when object is declared
➢ Automatically
called when object scope is over.
➢ Can be
overloaded. ➢ Can’t be
overloaded.
S. Strings as array and as pointer
char
*str=”Computer”; char s[]=”Computer”;
1.
sizeof(str) = 2 2. strlen(str) = 8
1.
sizeof(str) = 9 2. strlen(str) = 8
T. Multilevel Inheritance Multiple
Inheritance
A → B → C
A B
\ /
C
U. While Do..while
Works till
the condition is true. Executes atleast once even if the condition is false.
V File read and write
f.read((char*)&obj,sizeof(obj));
f.write((char*)&obj,sizeof(obj));
Two
parameters : (char*)&obj – explicit typecasting, converting object into
string of size of object passed as parameter 2 , sizeof(obj) and reads from
file and stores into object.
Two
parameters : (char*)&obj – explicit typecasting, converting object into
string of size of object passed as parameter 2 , sizeof(obj) and writes object
to file .
W. Function Prototype Function Defintion
Function
Header with list of parameters passed, return type mentioned, ended with a;.
Must match with Function header of defined body.
Function
containing body/statements to be executed.
X. Reference Variable typedef
Alternate
of a Variable . Int &ch=a; Ch is alternate name of a,share common location.
Typedef
gives name to a datatype. Typedef float amount;
Y. Function Overloading Function
Overriding
Overloading
- Two functions having same name and return Type, but with different type
Overriding
- When a function of base class is re-defined in the derived class.
and/or
number of arguments.
Z. Arrays Pointers
Array
–array use subscripted [] variable to access and manipulate the data ,array
variables can be equivalently written using pointer expression
Pointer
–pointer is a variables that hold the address of another variable .It is used
to manipulate data using the address, pointer use the * operator to access the
data pointed by them
Copy
constructors are called in following cases: a) when a function returns an
object of that class by value b) when the object of that class is passed by
value as an argument to a function c) when you construct an object based on
another object of the same class d) When compiler generates a temporary object
MORE Questions (Answer to the point)
1. What is
inheritance? 2. What is Polymorphism? 3. Is class an Object? Is object a class?
4. Why destructors invoke in reverse order? 5. What is role of constructor? 6.
Why we need constructors? 7. What property of OOP is implemented in
Constructors? 8. Can destructors be overloaded Yes/No & Why? 9. Can
constructors be overloaded Yes/No & Why? 10. What is difference between
default constructor and constructor with default arguments? 11. Does any value
is returned by Constructors? 12. Why the reference of an object is passed in
copy constructor? 13. When copy constructor is invoked? 14. From the given
conditions (1) Sample S1=S2; (2) S1=S2 ; When copy constructor will invoke. 15.
if a derived class has no parameters for its constructor but a base class has parameterized
constructor , how the constructor for the derived class would defined? 16.
Difference between for and while loop.
EXPECTED
VIVA questions(SOLVED)
What is a
class?
Class is
concrete representation of an entity. It represents a group of objects, which
hold similar attributes
and
behavior. It provides Abstraction and Encapsulations. Classes are generally
declared using the keyword
class.
2. What is
an Object? What is Object Oriented Programming?
Object
represents/resembles a Physical/real entity. An object is simply something you
can give a
name.
Object Oriented Programming is a Style of programming that represents a program
as a system
of objects
and enables code-reuse.
3. What is
Encapsulation?
Encapsulation
is binding of attributes and behaviors. Hiding the actual implementation and
exposing
the
functionality of any object. Encapsulation is the first step towards OOPS, is
the procedure of
covering
up of data and functions into a single unit (called class). Its main aim is to
protect the data
from out
side world
4. What is
Abstraction?
Hiding the
complexity. It is a process of defining communication interface for the
functionality and
hiding
rest of the things.
5. What is
Overloading?
Adding a
new method with the same name in same/derived class but with different
number/types of
parameters.
It implements Polymorphism.
6. What is
Inheritance?
It is a
process in which properties of object of one class acquire the properties of
object of another
class.
7. What is
an Abstract class?
An
abstract class is a special kind of class that cannot be instantiated. It
normally contains one or more
abstract
methods or abstract properties. It provides body to a class.
8. What is
Polymorphism? And its type?
1. What
do you mean by iostream.h?
2. What
is inheritance and its type?
3. What
is the difference b/n public, private and protected?
● Public:
The data members and methods having public as access outside the class.
●
Protected: The data members and methods declared as protected will be
accessible to the class methods and the derived class methods only.
● Private:
These data members and methods will be accessible not from objects created
outside the class. 4. What is a void return type?
A void
return type indicates that a method does not return a value.
5. What
is the difference between a while statement and a do statement?
A while
statement checks at the beginning of a loop to see whether the next loop
iteration should occur. A do statement checks at the end of a loop to see
whether the next loop iteration should occur.
6. What
is a nested class? Why can it be useful?
A
nested class is a class enclosed within the scope of another class. For
example: // Example 1: Nested class // class Outer Class {class Nested Class
{// ...}; //... What is preprocessor?
The
preprocessor is used to modify your program according to the preprocessor
directives in your source code. Preprocessor directives (such as #define) give
the preprocessor specific instructions on how to modify your source code. The
preprocessor reads in all of your include files and the source code you are
compiling and creates a preprocessed version of your source code. This
preprocessed version has all of its macros and constant symbols replaced by
their corresponding code and value assignments. If your source code contains
any conditional preprocessor directives (such as #if), the preprocessor
evaluates the condition and modifies your source code accordingly. The preprocessor
contains many features that are powerful to use, such as creating macros,
performing conditional compilation, inserting predefined environment variables
into your code, and turning compiler features on and off. For the professional
programmer, in-depth knowledge of the features of the preprocessor can be one
of the keys to creating fast, efficient programs.
7. What are memory management
operators?
There
are two types of memory management operators in C++:
● new
●
delete
Constructors
A special
function Always called whenever an instance of the class is created.
● Same
name as class name
● No
return type
●
Automatically call when object of class is created
● Used to
initialize the members of class
● class
Test
{ int a,b;
Test()
{ a=9;b=8;
} };
Here
Test() is the constructor of Class Test.
8. What is
copy constructor?
Constructor
which initializes it's object member variables ( by shallow copying) with
another
object of the same class. If you don't implement one in your class then
compiler
implements
one for you.
for
example:
○ Test
t1(10); // calling Test constructor
Test
t2(t1); // calling Test copy constructor
Test t2 =
t1;// calling Test copy constructor
● Copy
constructors are called in following cases:
● when a
function returns an object of that class by value
● when the
object of that class is passed by value as an argument to a function
● when you
construct an object based on another object of the same class
9. What is
default Constructor?
Constructor
with no arguments or all the arguments has default values. In Above Question
Test() is a
default
constructor
10. What
is a scope resolution operator?
A scope
resolution operator (::), can be used to define the member functions of a class
outside the
class.
1. What
are the advantages of inheritance?
It permits
code reusability. Reusability saves time in program development. It encourages
the reuse of
proven and
debugged high-quality software, thus reducing problem after a system becomes
functional
