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Final Review
Andy Wang
Object Oriented Programming in C++
COP 3330
Bitwise Operators
Built-in operators that allow accessing and manipulating
of individual bits
Necessary because smallest variables that can be
created are at least 1 byte
Accessing individual bits can be useful for making more
efficient algorithms, or using less storage space
The Bitwise Operators
Bitwise &.
Bitwise |
Performs the | operation on individual bits
Bitwise ^ (exclusive OR)
Performs the & operation on individual bits (1 is true, 0 is
false)
XOR is true if there is exactly one true and one false
Complement ~
Reverses the bits of a variable (1 -> 0, 0 -> 1)
The Bitwise Operators
<< (left shift)
Shifts the bits of a variable to the left
>> (right shift)
Shifts the bits of a variable to the right
Accessing Individual Bits
Understand the concept of a bit mask and how to create
one
Understand how to do these basic operations on a single
bit from a variable, without changing the other bits
stored in the variable
Set a bit to 1
Unset a bit (set to 0)
Flip a bit to its opposite
Query a bit (find out what it is—1 or 0)
You should be able to identify or derive how the above
operations are done on a single bit, with a combination
of an appropriate operation and a bit mask
Templates
Function templates
Functions that can work with multiple parameter types
Compiler builds a separate function for each needed type
An easy way to create overloaded functions without
writing individual version
Operations performed inside the function need to be valid
for types used in the calls
Class Templates
Extension of function template idea
Allows creation of a generic class, where the type of
item stored can vary
Again, operations used inside the class need to be valid
for any type used to instantiate the class
Each member function written as a function template
Template Declarations and
Object Instantiations
Use keyword template, along with template parameters
in angle brackets <>
template<class T>
template<typename T>
Examples
stack<double> myStack;
stack<int> stack2(10:
Data Structures
Basic data structure types
Stack—first in last out structure
Queue—first in first out structure
Vector—storage of a list using array-based storage
Linked-list—storage of a list in a linear format using selfreferential objects
A self-referential object contains data, along with one+
pointers, which point to other objects of the same type
Each node of a linked list stores a piece of data, and points to
the next node in the list
Tree—non-linear storage of a set of data using selfreferential objects
Each node in a tree has 2+ pointers to other nodes
Binary tree is good for soring and searching
Data Structures
Implementing basic data structures
Encapsulation of data structure inside an object means
details can be handled internally
Outside access through simpler interface
Often involves pointers and dynamic memory allocation
Templates are commonly used, to make data structures
more general
Some structures can be implemented with others
Through inheritance or composition
A stack can be implemented with a linked list of a vector
Exception Handling
A method of error-handling
Good for processing errors that must be handled in
places other than where they occurred
Good for handling errors from libraries or other
components
Should not be used for general program control
(confusing to the reader
Syntax
try { }
Label used for a block that encloses an area where
exception might be thrown
throw
Used to throw an exception
Can throw an item like a variable or an object
throw DivideByZeroException()
Also used to build a throw list
void function(int x) thorw (ThisException, ThatException)
Syntax
catch { }
The catch blocks immediately follow the try blocks
Can have more than one
Each catch can take one parameter, indicating the type of
exception
Special catch block catch(…) { }
Will catch any thrown exception
Useful for a default case—a “catch all”
Recursion
Recursive function
A function that calls itself
Recursion vs. iteration
Some example algorithms
Factorial, Fibonnaci, GCD, sorting, binary search
Miscellaneous
Conditional compilation
#define SYMBOL
#ifdef SYMBOL
Do something
#ifndef SYMBOL
Brings the symbol into existence
Do something
#endif
Code Writing Test Format
Specifications
Main program
Sample execution output
Your job
Write the declarations and definition files
Example Main Program
#include <iostream>
#include “flex.h”
using namespace std;
int main() {
Flex a, b(“Merry”), c(“Christmas”);
cout << a << ‘,’ << b << ‘,’ << c << endl;
b.cat(a);
cout << b << endl;
b.cat(c);
cout << b << endl;
c.cat(c); c.cat(c);
cout << c << endl;
return 0;
}
Example Output
* *,*Merry*,*Christmas*
*Merry *
*Merry Christmas*
*ChristmasChristmasChristmasChristmas*
Specifications
Objects of class Flex allow a variable length string to be
maintained
When the constructor for Flex is provided a c-string as a
parameter, the Flex object created will have that string
value.
If no parameter is provided, a default string consisting of
exactly one space should be created.
Flex should have an overload of the output operator
that will display the string surrounded by stars
Flex also has a void function, cat, having one reference
parameter of type Flex.
The function cat should append the string in that
parameter to the end of the Flex object invoking cat
Specifications
There is no established bound on the size of a Flex
object, so dynamic storage allocation should be used
All Flex member data is private
Show the content in flex.h and flex.cpp
It is okay to use the cstring library functions
