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Advanced Inheritance 539

16

18: String operator+(const String&);

19: void operator+=(const String&);

20: String & operator= (const String &);

21:

22: // General accessors

23: int GetLen()const { return itsLen; }

24: const char * GetString() const { return itsString; }

25: // static int ConstructorCount;

26:

27: private:

28: String (int); // private constructor

29: char * itsString;

30: unsigned short itsLen;

31:

32: };

33:

34: // default constructor creates string of 0 bytes

35: String::String()

36: {

37: itsString = new char[1];

38: itsString[0] = ‘\0’;

39: itsLen=0;

40: // cout << “\tDefault string constructor\n”;

41: // ConstructorCount++;

42: }

43:

44: // private (helper) constructor, used only by

45: // class methods for creating a new string of

46: // required size. Null filled.

47: String::String(int len)

48: {

49: itsString = new char[len+1];

50: for (int i = 0; i<=len; i++)

51: itsString[i] = ‘\0’;

52: itsLen=len;

53: // cout << “\tString(int) constructor\n”;

54: // ConstructorCount++;

55: }

56:

57: // Converts a character array to a String

58: String::String(const char * const cString)

59: {

60: itsLen = strlen(cString);

61: itsString = new char[itsLen+1];

62: for (int i = 0; i<itsLen; i++)

63: itsString[i] = cString[i];

64: itsString[itsLen]=’\0’;

65: // cout << “\tString(char*) constructor\n”;

66: // ConstructorCount++;

67: }

68:

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