C++

ONLY TWO FILES ALLOWED: MYSTRING.CPP, MYSTRING.H

PREVIOUS ASSIGNMENT:

Write a string class. To avoid conflicts with other similarly named classes, we will call our version MyString. This object is designed to make working with sequences of characters a little more convenient and less error-prone than handling raw c-strings, (although it will be implemented as a c-string behind the scenes). The MyString class will handle constructing strings, reading/printing, and accessing characters. In addition, the MyString object will have the ability to make a full deep-copy of itself when copied.

Your class must have only one data member, a c-string implemented as a dynamic array. In particular, you must not use a data member to keep track of the size or length of the MyString.

This is the first part of a two part assignment. In the next assignment you will be making some refinements to the class that you create in this assignment. For example, no documentation is required this week, but full documentation will be required next week.

Here is a list of the operations this class must support:

A length member function which returns the number of characters in the string. Use strlen().

Construction of a MyString from a const c-string. You should copy the string data, not just store a pointer to an argument passed to the constructor. Constructing a MyString with no arguments creates an empty MyString object (i.e. ""). A MyString object should be implemented efficiently (space-wise) which is to say you should not have a fixed-size buffer of chars, but instead allocate space for chars on an as-needed basis. Use strcpy().

Printing a MyString to a stream using an overloaded << (insertion) operator, which should simply print out its characters. Use <<.

Your MyString object should overload the square brackets [ ] operator to allow direct access to the individual characters of the string. This operation should range-check and assert if the index is out of bounds. You will write two versions of the [ ] operator, a const version that allows read access to the chars, and a non-const version that returns the client a reference to the char so they can change the value.

All six of the relational operators (<, <=, >, >=, ==, !=) should be supported. They should be able to compare MyString objects to other MyStrings as well as MyStrings to c-strings. The ordering will be based on ASCII values. You can think of this as essentially alphabetical order; however, because of the way that ASCII values are defined, uppercase letters will always come before lowercase letters, and punctuation will make things even more complicated. Confused? You don't need to worry about any of this: just use the results of calling the strcmp() function. MyStrings or c-strings should be able to appear on either side of the comparison operator.

Of course, you'll also need to include the four functions discussed in the lesson that are always required in classes that use dynamic memory. (These functions, excluding the default constructor, are otherwise known as the "big-three".)

You may use all of the c-string functionality provided by C++. This will include the strlen(), strcmp(), and strcpy() functions, along with the overloaded insertion operator for c-strings. These functions are all covered in detail in the text. When you use strcpy() treat it as a void function despite the fact that it has a return value. Do not use strncpy(), strncat(), or strncmp() since they are not implemented in all versions of C++. You may NOT use anything from the C++ string class!!

Unfortunately, Visual C++ will, under its default settings, report an error when you try to use strcpy() or strcat(), even though they are standard C++. You can prevent this by adding this line as the first line in your file:

#pragma warning(disable:4996) 

You must place your header file and implementation file in a namespace. Normally one would call a namespace something more likely to be unique, but for purposes of convenience we will call our namespace "cs_mystring".

CURRENT ASSIGNMENT:

This week you'll be making the following refinements to the class that you wrote in the last assignment. All the requirements from that class still apply. For example, all MyStrings must always be stored in a dynamic array that is exactly the correct size to store the string.

Extraction Operator [10 points]

Just like the >> operator that reads C-strings, your >> operator should skip any leading spaces and then read characters into the string up to the first whitespace character.

For reasons of convenience, we will impose a limit of 127 on the number of characters this function will read. This is so you can temporarily read into a non-dynamic array and then copy what you need into your data member, which will be a dynamic array. Note that this does not mean that all MyStrings will always have a maximum of 127 characters. For example, you might get a MyString with more than 127 characters by using the MyString constructor or by concatenating two MyStrings.

Hint: Don't try to read character by character in a loop. Use the extraction operator to do the reading of the input into a non-dynamic array, then use strcpy() to copy it into your data member. Make sure to allocate the correct amount of memory.

Hint: if you use the extraction operator as suggested above, you will not have to skip leading whitespace, because the extraction operator does that for you.

A read() function [10 points]

The read() function will allow the client programmer to specify the delimiting character (the one to stop at instead of the first space). This will be a void function that will take two arguments, a stream and the delimiting character. It should not skip leading spaces. The limit of 127 characters imposed on the >> function above also applies to this function.

Hint: Don't try to read character by character in a loop. Use the in.getline() function to do the reading of the input into a non-dynamic array, then use strcpy() to copy it into your data member.

Concatenation Operator [10 points]

Overload the + operator to do MyString concatenation. The operator must be able to handle either MyString objects or C-strings on either side of the operator. Be careful with the memory management here. You'll have to allocate enough memory to hold the new MyString. I suggest using strcpy() to get the left operand into the result MyString, and then strcat() to append the right operand. Both strcpy() and strcat() should be used as if they are void, even though they do have return values.

Combined Concatenation/Assignment Operator [5 points]

Overload the shorthand += to combine concatenation and assignment. Only MyStrings can be on the left-hand side of a += operation, but either MyStrings or C-strings may appear on the right side. If you pay close attention to the += operator from the feetInches class, these may be the easiest points of the semester.

Add Documentation [10 points]

Hints about reading input files:

I suggest that you copy the text from the input file webpage and paste it into a file that you have created using your IDE. The files you create when you type in your IDE are always text files (even if they don't end with .txt). If you're using Windows, you could also use Notepad, but there's no reason to open another application when you are already working in your IDE. I strongly suggest that you don't use TextEdit (Mac) or Word, because these do not store files as text files by default.

Here is important information about where to save your input file so that your IDE can find it

Extensions are part of the file name. If you want read from a file named "myfile.txt", typing "myfile" or "myfile.cpp" won't work.

For Windows users, before you start this assignment, I suggest that you make sure that Windows is showing you the complete file name of your files, including the extensions. Windows hides this from you by default. In Windows 7 and 8 the procedure is as follows:

Choose "control panel" from the start menu

Choose "Folder Options" from the list of control panel items. In Windows 8 you may have to type "Folder Options" into the control panel search bar.

Choose the "view" tab from the Folder Options window

Find the checkbox that says "Hide extensions for known file types".

Uncheck that checkbox.

In Windows 10 the procedure is: go to file explorer and click "View" on the toolbar, then go to "Options" on the furthest right, click on the drop down arrow and choose "Change folder and search options". Click "View" on the top and uncheck "Hide extensions for known file types"

CLIENT:

/* * ------------------- * These functions are designed to help you test your MyString objects, * as well as show the client usage of the class. * * The BasicTest function builds an array of strings using various * constructor options and prints them out. It also uses the String * stream operations to read some strings from a data file. * * The RelationTest function checks out the basic relational operations * (==, !=, <, etc) on Strings and char *s. * * The ConcatTest functions checks the overloaded + and += operators that * do string concatenation. * * The CopyTest tries out the copy constructor and assignment operators * to make sure they do a true deep copy. * * Although not exhaustive, these tests will help you to exercise the basic * functionality of the class and show you how a client might use it. * * While you are developing your MyString class, you might find it * easier to comment out functions you are ready for, so that you don't * get lots of compile/link complaints. */ #include "mystring.h" #include  #include  // for toupper() #include  #include  #include  using namespace std; using namespace cs_mystring; void BasicTest(); void RelationTest(); void ConcatTest(); void CopyTest(); MyString AppendTest(const MyString& ref, MyString val); string boolString(bool convertMe); int main() { BasicTest(); RelationTest(); ConcatTest(); CopyTest(); } string boolString(bool convertMe) { if (convertMe) { return "true"; } else { return "false"; } } void BasicTest() { MyString s; int stringLength; cout << "----- Testing basic String creation & printing" << endl; const MyString strs[] = {MyString("Wow"), MyString("C++ is neat!"), MyString(""), MyString("a-z")}; for (int i = 0; i < 4; i++){ cout << "string [" << i <<"] = " << strs[i] << endl; } cout << endl << "----- Now reading MyStrings from file" << endl; cout << endl << "----- first, word by word" << endl; ifstream in("mystring.txt"); assert(in); while (in.peek() == '#'){ in.ignore(128, ' '); } in >> s; while (in) { cout << "Read string = " << s << endl; in >> s; } in.close(); cout << endl << "----- now, line by line" << endl; ifstream in2("mystring.txt"); assert(in2); while (in2.peek() == '#'){ in2.ignore(128, ' '); } s.read(in2, ' '); while (in2) { cout << "Read string = " << s << endl; s.read(in2, ' '); } cout << endl << "----- Testing access to characters (using const)" << endl; const MyString s1("abcdefghijklmnopqsrtuvwxyz"); cout << "Whole string is " << s1 << endl; cout << "now char by char: "; stringLength = s1.length(); for (int i = 0; i < stringLength; i++){ cout << s1[i]; } cout << endl << "----- Testing access to characters (using non-const)" << endl; MyString s2("abcdefghijklmnopqsrtuvwxyz"); cout << "Start with " << s2; stringLength = s2.length(); for (int i = 0; i < stringLength; i++){ s2[i] = toupper(s2[i]); } cout << " and convert to " << s2 << endl; } void RelationTest() { cout << " ----- Testing relational operators between MyStrings "; const MyString strs[] = {MyString("app"), MyString("apple"), MyString(""), MyString("Banana"), MyString("Banana")}; for (int i = 0; i < 4; i++) { cout << "Comparing " << strs[i] << " to " << strs[i+1] << endl; cout << "\tIs left < right? " << boolString(strs[i] < strs[i+1]) << endl; cout << "\tIs left <= right? " << boolString(strs[i] <= strs[i+1]) << endl; cout << "\tIs left > right? " << boolString(strs[i] > strs[i+1]) << endl; cout << "\tIs left >= right? " << boolString(strs[i] >= strs[i+1]) << endl; cout << "\tDoes left == right? " << boolString(strs[i] == strs[i+1]) << endl; cout << "\tDoes left != right ? " << boolString(strs[i] != strs[i+1]) << endl; } cout << " ----- Testing relations between MyStrings and char * "; MyString s("he"); const char *t = "hello"; cout << "Comparing " << s << " to " << t << endl; cout << "\tIs left < right? " << boolString(s < t) << endl; cout << "\tIs left <= right? " << boolString(s <= t) << endl; cout << "\tIs left > right? " << boolString(s > t) << endl; cout << "\tIs left >= right? " << boolString(s >= t) << endl; cout << "\tDoes left == right? " << boolString(s == t) << endl; cout << "\tDoes left != right ? " << boolString(s != t) << endl; MyString u("wackity"); const char *v = "why"; cout << "Comparing " << v << " to " << u << endl; cout << "\tIs left < right? " << boolString(v < u) << endl; cout << "\tIs left <= right? " << boolString(v <= u) << endl; cout << "\tIs left > right? " << boolString(v > u) << endl; cout << "\tIs left >= right? " << boolString(v >= u) << endl; cout << "\tDoes left == right? " << boolString(v == u) << endl; cout << "\tDoes left != right ? " << boolString(v != u) << endl; } void ConcatTest() { cout << " ----- Testing concatentation on MyStrings "; const MyString s[] = {MyString("outrageous"), MyString("milk"), MyString(""), MyString("cow"), MyString("bell")}; for (int i = 0; i < 4; i++) { cout << s[i] << " + " << s[i+1] << " = " << s[i] + s[i+1] << endl; } cout << " ----- Testing concatentation between MyString and char * "; const MyString a("abcde"); const char *b = "XYZ"; cout << a << " + " << b << " = " << a + b << endl; cout << b << " + " << a << " = " << b + a << endl; cout << " ----- Testing shorthand concat/assign on MyStrings "; MyString s2[] = {MyString("who"), MyString("what"), MyString("WHEN"), MyString("Where"), MyString("why")}; for (int i = 0; i < 4; i++) { cout << s2[i] << " += " << s2[i+1] << " = "; cout << (s2[i] += s2[i+1]) << "and"; cout << s2[i] << endl; } cout << " ----- Testing shorthand concat/assign using char * "; MyString u("I love "); const char *v = "programming"; cout << u << " += " << v << " = "; cout << (u += v) << endl; } MyString AppendTest(const MyString& ref, MyString val) { val[0] = 'B'; return val + ref; } void CopyTest() { cout << " ----- Testing copy constructor and operator= on MyStrings "; MyString orig("cake"); MyString copy(orig); // invoke copy constructor copy[0] = 'f'; // change first letter of the *copy* cout << "original is " << orig << ", copy is " << copy << endl; MyString copy2; // makes an empty string copy2 = orig; // invoke operator= copy2[0] = 'f'; // change first letter of the *copy* cout << "original is " << orig << ", copy is " << copy2 << endl; copy2 = "Copy Cat"; copy2 = copy2; // copy onto self and see what happens cout << "after self assignment, copy is " << copy2 << endl; cout << "Testing pass & return MyStrings by value and ref" << endl; MyString val = "winky"; MyString sum = AppendTest("Boo", val); cout << "after calling Append, sum is " << sum << endl; cout << "val is " << val << endl; val = sum; cout << "after assign, val is " << val << endl; } 

DATA FILE:

# This file has some strings that are used in the string test to check # reading strings from files. The default overloaded >> of your string # class should skip over any leading spaces and read characters into # the string object, stopping at the first whitespace character (this is # similar to the behavior of >> on char *). The read method of the # string class is a little fancier. It allows client to restrict # how many characters at max to read and what character to use as # delimiter, so you can stop at newline instead of space, for example. # Reading consumes the delimiting character, so the next read starts # after that. # The first time we will read individual words, next we read whole lines 

REQUIRED OUTPUT:

----- Testing basic String creation & printing string [0] = Wow string [1] = C++ is neat! string [2] = string [3] = a-z ----- Now reading MyStrings from file ----- first, word by word Read string = The Read string = first Read string = time Read string = we Read string = will Read string = read Read string = individual Read string = words, Read string = next Read string = we Read string = read Read string = whole Read string = lines ----- now, line by line Read string = The first time we will Read string = read individual words, next Read string = we read whole lines ----- Testing access to characters (using const) Whole string is abcdefghijklmnopqsrtuvwxyz now char by char: abcdefghijklmnopqsrtuvwxyz ----- Testing access to characters (using non-const) Start with abcdefghijklmnopqsrtuvwxyz and convert to ABCDEFGHIJKLMNOPQSRTUVWXYZ ----- Testing relational operators between MyStrings Comparing app to apple Is left < right? true Is left <= right? true Is left > right? false Is left >= right? false Does left == right? false Does left != right ? true Comparing apple to Is left < right? false Is left <= right? false Is left > right? true Is left >= right? true Does left == right? false Does left != right ? true Comparing to Banana Is left < right? true Is left <= right? true Is left > right? false Is left >= right? false Does left == right? false Does left != right ? true Comparing Banana to Banana Is left < right? false Is left <= right? true Is left > right? false Is left >= right? true Does left == right? true Does left != right ? false ----- Testing relations between MyStrings and char * Comparing he to hello Is left < right? true Is left <= right? true Is left > right? false Is left >= right? false Does left == right? false Does left != right ? true Comparing why to wackity Is left < right? false Is left <= right? false Is left > right? true Is left >= right? true Does left == right? false Does left != right ? true ----- Testing concatentation on MyStrings outrageous + milk = outrageousmilk milk + = milk + cow = cow cow + bell = cowbell ----- Testing concatentation between MyString and char * abcde + XYZ = abcdeXYZ XYZ + abcde = XYZabcde ----- Testing shorthand concat/assign on MyStrings who += what = whowhatandwhowhat what += WHEN = whatWHENandwhatWHEN WHEN += Where = WHENWhereandWHENWhere Where += why = WherewhyandWherewhy ----- Testing shorthand concat/assign using char * I love += programming = I love programming ----- Testing copy constructor and operator= on MyStrings original is cake, copy is fake original is cake, copy is fake after sElf assignment, copy is Copy Cat Testing pass & return MyStrings by value and ref after calling Append, sum is BinkyBoo val is winky after assign, val is BinkyBo