Description
This week’s assignment will have you write a program that has you create your own simple version of
the C++ string class. Your solution must not use the standard C++ string class though (only C-style
strings). Feel free to work in pairs and ask for help early.
Write a program that defines a class called String. The class must have a data member that is an
array of 80 characters to store the characters of the string (therefore, the largest number of characters in
an object of type String, including the null character at the end, is 80). A proper empty object of type
String should have a single character it in, the null character (‘\0’), located in the first array element.
The public interface of the class must provide the following:
• A default constructor that creates an empty string
• A constructor that accepts a C-string parameter and sets the internal character array with it
• A member function called copy() that accepts a single C-string parameter and copies the
value of the argument into the current object, overwriting whatever was in the object before (see
NOTE below)
• A member function called concat()that accepts a single C-string parameter and appends the
value of the argument to the end of the internal string in the object (see NOTE below)
• A member function called size() that returns the size of the internal string in the object, not
including the null character
• A member function called str()that returns a constant pointer to the current C string in the
object, that same as the c_str() member function of the C++ string class does.
NOTE: If the C-string passed to the single parameter constructor, copy() or concat() member
functions would cause the internal character array to be overflowed, then the function should copy
whatever can be copied and make sure that the last character is set to the null character (‘\0’).
You are free to use any of the C-string library functions, if you like, or you may implement the
functionality without using any library functions. It is up to you.
Your program will consist of three files:
• A header file named String.h
• An implementation file for the header file, named String.cpp
• A main program file named main.cpp
The main program, main.cpp, has been provided for you. You will use this file as-is, except for the
addition of your preamble. It is your task to create the header and implementation files and then write
the correct class definition and member function definitions to make the main work. While the main to
use for your final submission is provided, you will likely want/need to use some intermediate driver
programs to test and verify your work as you make progress.
CSCI 136 Supervised Programming Lab
Lab Assignment #11
Fall 2014 Page 2
Submitting your work
Each of your source code files must have a preamble at the top (see the programming rules and
guidelines document in Blackboard for more on the preamble).
Make sure you are in the folder with your source code files (use the ls command) and then run the
following to create a zip archive of them:
$ mkdir lastname_firstname_lab11
$ cp main.cpp lastname_firstname_lab11/main.cpp
$ cp String.h lastname_firstname_lab11/String.h
$ cp String.cpp lastname_firstname_lab11/String.cpp
$ zip –r lastname_firstname_lab11.zip lastname_firstname_lab11/
You’ll need to change lastname and firstname to your actual last and first names (use lowercase
letters) in the steps above. Once you have your zipfile, you can use that file as your submission for the
assignment in Blackboard.
Sample output
$ ./lab11
s1 =
s1.size() = 0
s2 = Test string
s2.size() = 11
s3 = A test string that is definitely going to be too long and should therefore be t
s3.size() = 79
s1 = Another test string
s1.size() = 19
s2 = The fourth test string is fairly long, although just shy of being truncated.
s2.size() = 76
s3 = Another test string that is definitely too long and should therefore be truncat
s3.size() = 79
s1 = Another test string: is still a string,
even with a newline.
s1.size() = 60
s2 = The fourth test string is fairly long, although just shy of being truncated.PAR
s2.size() = 79
s3 = Another test string that is definitely too long and should therefore be truncat
s3.size() = 79
s1 = Final s1 string.
s1.size() = 16
s2 = Final s2 string.
s2.size() = 16
s3 = Final s3 string.
s3.size() = 16
