Operator Overloading Test Failure

Question

Build is successful, but the test case #2 keep failing. I don't know what to change or fix. The test program says that

Test Case #2 operator <=() FAILED and operator >() Failed.

Here is My header

#ifndef MYSTRING_H

#define MYSTRING_H

#include <iostream>

#include <cstring> //library functions 

#include <cstdlib> //exit() function 
using namespace std;


// MyString class
class MyString
{
private:
char *str;
int len;

public:
//constructor
MyString()
{
    *str = 0;
    len = 0;
}

// convert and copy constructors. 
MyString(char *);
MyString(MyString &);


// Destructor. 
~MyString()
{
    if (len != 0)
        delete[]  str;
    str = 0;
    len = 0;
}
// operators.   
int length() { return len; }
char *getValue() { return str; };

//==
bool operator==(MyString &);

//!=
bool operator!=(MyString &);

//>
bool operator>(MyString &);

//<
bool operator<(MyString &);

//>=
bool operator>=(MyString &);

//<=
bool operator<=(MyString &);

// insertion and extraction operators.
friend ostream &operator<<(ostream &, const MyString &);
};
// NOTE: Below is the implementation for the functions that are declared   above

//constructor
MyString::MyString(char *sptr)
{
len = strlen(sptr);

str = new char[len + 1];

strcpy(str, sptr);
}
//Copy Constructor
MyString::MyString(MyString &right)
{
str = new char[right.length() + 1];

strcpy(str, right.getValue());

len = right.length();
}

//==
bool MyString::operator==(MyString &right) 
{
return !strcmp(str, right.getValue());
}

//!=
bool MyString::operator!=(MyString &right)
{
return strcmp(str, right.getValue());
}
//>
bool MyString::operator>(MyString &right)
{
if (strcmp(str, right.getValue()) > 0)
    return true;
else
    return false;
}

//<
bool MyString::operator<(MyString &right)
{
if (strcmp(str, right.getValue()) < 0)
    return true;
else
    return false;
}

//>=
bool MyString::operator>=(MyString &right)
{
if (strcmp(str, right.getValue()) >= 0)
    return true;
else
    return false;

}

//<=
bool MyString::operator<=(MyString &right)
{
if (strcmp(str, right.getValue()) <= 0)
    return true;
else
    return false;

}

//stream operators
ostream &operator<<(ostream &strm, const MyString &obj)
{
strm << obj.str;
 return strm;
}

#endif

And here is the test program.

#include "stdafx.h"

#include <iostream>

#include "MyString.h"

using namespace std;

// Declare a new datatype that defines requires test case parameters
typedef struct {
char str1[128];
char str2[128];
bool equalNotEqual;
bool lessThan;
bool lessThanEqual;
bool greaterThan;
bool greaterThanEqual;
bool testPassed;
} TEST_CASE;

// Declare various test cases used to test the MyString object                          
TEST_CASE testCases[] = {
/* str1           str2         ==       <       <=       >       >=     P/F flag                                                        */
{ "test",        "test",      true,   false,   true,   false,   true,     true },
{ "test",        "Test",      false,  false,   true,   false,   true,     true },
{ "test",        "test1",     false,  true,    true,   false,   false,    true },
{ "test ",       "test",      false,  false,   false,  true,    true,     true }
};


// Main programentry point
int main()
{

// Flag used to determine if any test case failed
bool failed = false;

// Loop through all test cases
for (int i = 0; i < sizeof(testCases) / sizeof(TEST_CASE); ++i)
{

    // Instantiate two MyString objects that will be used to test overloaded operators
    MyString myStrObj1(testCases[i].str1);
    MyString myStrObj2(testCases[i].str2);

    cout << "Test Case #" << i + 1 << endl;

    //-------------------------
    // Test the operator==()
    //vvvvvvvvvvvvvvvvvvvvvvvvv
    if ((myStrObj1 == myStrObj2) != testCases[i].equalNotEqual)
    {
        cout << "\t***** operator==() FAILED" << endl;
        testCases[i].testPassed = false;
    }

    //-------------------------
    // Test the operator!=()
    //vvvvvvvvvvvvvvvvvvvvvvvvv
    if ((myStrObj1 != myStrObj2) == testCases[i].equalNotEqual)
    {
        cout << "\t***** operator!=() FAILED" << endl;
        testCases[i].testPassed = false;
    }

    //-------------------------
    // Test the operator<()
    //vvvvvvvvvvvvvvvvvvvvvvvvv
    if ((myStrObj1 < myStrObj2) != testCases[i].lessThan)
    {
        cout << "\t***** operator<() FAILED" << endl;
        testCases[i].testPassed = false;
    }

    //-------------------------
    // Test the operator<=()
    //vvvvvvvvvvvvvvvvvvvvvvvvv
    if ((myStrObj1 <= myStrObj2) != testCases[i].lessThanEqual)
    {
        cout << "\t***** operator<=() FAILED" << endl;
        testCases[i].testPassed = false;
    }

    //-------------------------
    // Test the operator>()
    //vvvvvvvvvvvvvvvvvvvvvvvvv
    if ((myStrObj1 > myStrObj2) != testCases[i].greaterThan)
    {
        cout << "\t***** operator>() FAILED" << endl;
        testCases[i].testPassed = false;
    }

    //-------------------------
    // Test the operator>=()
    //vvvvvvvvvvvvvvvvvvvvvvvvv
    if ((myStrObj1 >= myStrObj2) != testCases[i].greaterThanEqual)
    {
        cout << "\t***** operator>=() FAILED" << endl;
        testCases[i].testPassed = false;
    }

    // Use the ostream operator to display the string stored in the MyString operator 
    cout << "The string should be \'" << testCases[i].str1 << "\' string   returned from MyClass \'" << myStrObj1 << "\'" << endl << endl;

    // Did this test case passed?
    //vvvvvvvvvvvvvvvvvvvvvvvvvvvvv
    if (testCases[i].testPassed)
    {
        // yes!!!
        cout << "Test Case #" << i + 1 << " PASSED!!!!" << endl << endl;
    }
    else
    {
        // Nope, set failed flag
        failed = true;
    }
} /* end of for loop */

  //-------------------------
  // Display Overall Status
  //vvvvvvvvvvvvvvvvvvvvvvvvv
if (!failed)
{
    cout << "**************************" << endl;
    cout << "***** OVERALL PASSED *****" << endl;
    cout << "**************************" << endl;
}
else
{
    cout << "**************************" << endl;
    cout << "***** OVERALL FAILED *****" << endl;
    cout << "**************************" << endl;
}

return 0;
}

Thanks is advance for any help.

Answer 1

"[The strcmp] function starts comparing the first character of each string. If they are equal to each other, it continues with the following pairs until the characters differ or until a terminating null-character is reached. This function performs a binary comparison of the characters."

Since 't' is greater than 'T', "test" is greater than "Test" by this rule. Perhaps you're expecting strcmp to do something more than it actually does, such as implement English language rules for word comparisons. Have a look at things like std::collate.