Managing Arrays and Strings 43913
78:
79: // operator equals, frees existing memory
80: // then copies string and size
81: String& String::operator=(const String & rhs)
82: {
83: if (this == &rhs)
84: return *this;
85: delete [] itsString;
86: itsLen=rhs.GetLen();
87: itsString = new char[itsLen+1];
88: for (unsigned short i = 0; i<itsLen;i++)
89: itsString[i] = rhs[i];
90: itsString[itsLen] = ‘\0’;
91: return *this;
92: }
93:
94: //nonconstant offset operator, returns
95: // reference to character so it can be
96: // changed!
97: char & String::operator[](unsigned short offset)
98: {
99: if (offset > itsLen)
100: return itsString[itsLen-1];
101: else
102: return itsString[offset];
103: }
104:
105: // constant offset operator for use
106: // on const objects (see copy constructor!)
107: char String::operator[](unsigned short offset) const
108: {
109: if (offset > itsLen)
110: return itsString[itsLen-1];
111: else
112: return itsString[offset];
113: }
114:
115: // creates a new string by adding current
116: // string to rhs
117: String String::operator+(const String& rhs)
118: {
119: unsigned short totalLen = itsLen + rhs.GetLen();
120: String temp(totalLen);
121: unsigned short i;
122: for ( i= 0; i<itsLen; i++)
123: temp[i] = itsString[i];
124: for (unsigned short j = 0; j<rhs.GetLen(); j++, i++)
125: temp[i] = rhs[j];
126: temp[totalLen]=’\0’;
127: return temp;LISTING13.14 continued