#include <iostream>
#include <string.h>
using namespace std;
class String
{
public:
String();
String(const char *const);
String(const String &);
~String();
char & operator[](int offset);
char operator[](int offset) const;
String operator+(const String&);
void operator+=(const String&);
String & operator= (const String &);
friend ostream& operator<<( ostream& theStream,String& theString);
int GetLen()const { return itsLen; }
const char * GetString() const { return itsString; }
private:
String (int);
char * itsString;
unsigned short itsLen;
};
String::String(){
itsString = new char[1];
itsString[0] = '\0';
itsLen=0;
}
String::String(int len)
{
itsString = new char[len+1];
for (int i = 0; i<=len; i++)
itsString[i] = '\0';
itsLen=len;
}
String::String(const char * const cString)
{
itsLen = strlen(cString);
itsString = new char[itsLen+1];
for (int i = 0; i<itsLen; i++)
itsString[i] = cString[i];
itsString[itsLen]='\0';
}
String::String (const String & rhs)
{
itsLen=rhs.GetLen();
itsString = new char[itsLen+1];
for (int i = 0; i<itsLen;i++)
itsString[i] = rhs[i];
itsString[itsLen] = '\0';
}
String::~String ()
{
delete [] itsString;
itsLen = 0;
}
String& String::operator=(const String & rhs)
{
if (this == &rhs)
return *this;
delete [] itsString;
itsLen=rhs.GetLen();
itsString = new char[itsLen+1];
for (int i = 0; i<itsLen;i++)
itsString[i] = rhs[i];
itsString[itsLen] = '\0';
return *this;
}
char & String::operator[](int offset){
if (offset > itsLen)
return itsString[itsLen-1];
else
return itsString[offset];
}
char String::operator[](int offset) const
{
if (offset > itsLen)
return itsString[itsLen-1];
else
return itsString[offset];
}
String String::operator+(const String& rhs)
{
int totalLen = itsLen + rhs.GetLen();
String temp(totalLen);
int i, j;
for (i = 0; i<itsLen; i++)
temp[i] = itsString[i];
for (j = 0; j<rhs.GetLen(); j++, i++)
temp[i] = rhs[j];
temp[totalLen]='\0';
return temp;
}
void String::operator+=(const String& rhs)
{
unsigned short rhsLen = rhs.GetLen();
unsigned short totalLen = itsLen + rhsLen;
String temp(totalLen);
int i, j;
for (i = 0; i<itsLen; i++)
temp[i] = itsString[i];
for (j = 0, i = 0; j<rhs.GetLen(); j++, i++)
temp[i] = rhs[i-itsLen];
temp[totalLen]='\0';
*this = temp;
}
ostream& operator<< ( ostream& theStream,String& theString)
{
theStream << theString.itsString;
return theStream;
}
int main()
{
String theString("Hello world.");
cout << theString;
return 0;
}
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