MYSTRING_H MyString.h
#ifndef #define MYSTRING_H #include <iostream> using namespace std; class MyString; //Forward Declaration ostream& operator<<(ostream&, const MyString&); istream& operator>>(istream&, MyString&); class MyString { private: char* str; int len; public: MyString(); MyString(MyString& right); MyString(char* sptr); ~MyString(); int length(); const char* getValue(); // overloaded operators const MyString operator+=(MyString &); const char *operator+=(const char *); const MyString operator=(MyString &); const char *operator=(const char *); int operator==(MyString &); int operator==(const char *); int operator!=(MyString &); int operator!=(const char *); bool operator>(MyString &); bool operator>(const char *); bool operator<(const char *); bool operator<(MyString &); bool operator>=(const char*); bool operator>=(MyString &); bool operator<=(const char *); bool operator<=(MyString &); friend ostream &operator<<(ostream &, const MyString &); friend istream &operator>>(istream &, MyString &); }; #endif
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MyString.cpp
#include <iostream> #include "MyString.h" using namespace std; MyString::MyString() { str = NULL; len = 0; } MyString::MyString(MyString& right) { str= new char[right.length() + 1]; strcpy(str, right.getValue()); len = right.length(); } MyString::MyString(char* sptr) { len = strlen(sptr); str = new char[len + 1]; strcpy(str, sptr); } MyString::~MyString() { if(len != 0) delete [] str; } int MyString::length() { return len; } const char* MyString::getValue() { return str; } /* Overloaded = operator. Called when operand on the right is another MyString object. Returns the calling object */ const MyString MyString::operator=(MyString& right) { if (len != 0) delete [] str; str = new char[right.length() + 1];
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}
strcpy(str, right.getValue()); len = right.length(); return *this;
/* Overloaded = operator Called when operand on the right is a C-string returns the str member of the calling object */ const char* MyString::operator=(const char* right) { if (len != 0) delete [] str; len = strlen(right); str = new char [len + 1]; strcpy(str, right); return str; } /* Overloaded += operator. CAlled when operand on the right is another MyString object. Concatenates the str member of right to the str member of the calling object. returns the calling object */ const MyString MyString::operator+=(MyString& right) { char * temp = str; str = new char[strlen(str) + right.length() + 1]; strcpy(str, temp); strcat(str, right.getValue()); if(len != 0) delete [] temp; len = strlen(str); return *this; } /* Overloaded += operator. Called when the operand on the right is a string. Concatenates the str member of right to the str member of the calling object. Returns the str member of the calling object. */ const char* MyString::operator += (const char* right) { char* temp = str; str = new char[strlen(str) + strlen(right) + 1]; strcpy(str, temp); strcat(str, right); if(len != 0) delete [] temp; return str; }
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/* Overloaded == operator. Called when the operand on the right is a MyString object. Returns true if right.str is the same as */ str int MyString::operator==(MyString& right) { return !strcmp(str, right.getValue()); } /* Overloaded == operator. Called when the operand on the right is a C-String. Returns true if right is the same as str */ int MyString::operator==(const char* right) { return !strcmp(str, right); } /* Overloaded != operator. Called when the operand on the right is a MyString object. Returns true if right.str is not the same as str */ int MyString::operator!=(MyString& right) { return strcmp(str, right.getValue()); } /* Overloaded == operator. Called when the operand on the right is a C-String. Returns true if right is not the same as str */ int MyString::operator!=(const char* right) { return strcmp(str, right); } /* Overloaded > operator. Called when the operand on the right is a MyString object. Returns true if str is greater than right.str */ bool MyString:: operator>(MyString& right) { bool status; if(strcmp(str, right.getValue()) > 0) status = true; else status = false; return status;
}
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/* Overloaded > operator. Called when the operand on the right is a C-String. Returns true if str is greater than right */ bool MyString:: operator>(const char* right) { bool status; if(strcmp(str, right) > 0) status = true; else status = false; return status; } /* Overloaded < operator. Called when the operand on the right is a MyString object. Returns true if str is less than right.str */ bool MyString::operator<(MyString& right) { bool status; if(strcmp(str, right.getValue()) < 0) status = true; else status = false; return status; } /* Overloaded < operator. Called when the operand on the right is a C-String. Returns true if str is less than right */ bool MyString:: operator<(const char* right) { bool status; if(strcmp(str, right) < 0) status = true; else status = false; return status; } /* Overloaded >= operator. Called when the operand on the right is a MyString object. Return...