1. C++ New Types

2. Enumeration type (1) enum fruit_tea{apple, banana, orange};
fruit_tea taste;
if (taste==apple) cout<<“Taste like apple.”;
else if (taste==banana) cout<<“Taste like banana.”;
else cout<<“Taste like orange.”;
cout<<apple<<“,”<<banana<<“,”<<orange<<endl;

3. Enumeration type (2) enum fruit_tea{apple, banana, orange};
enum boolean {unknow=-1, false, true, off=0, on, yes};
//on=1, yes=2
enum gender{male, female} gender, animal[15];
//enumeration type 名稱可與變數名稱相同
enum {red, green, blue} color;
//enumeration type 名稱可省略

4. struct, union and class
{struct|union|class} type_name {members} variable_name;

5. struct struct Time { int hour; int minute; int second; };
Time timeObject;
Time timeArray[ 10 ];
Time *timePtr;
Time &timeRef = timeObject;

6. struct Dot operator (.) for structure and class members
Arrow operator (->) for structure and class members via pointer to object
Print member hour of timeObject:
cout << timeObject.hour; OR
timePtr = &timeObject; cout << timePtr->hour;
timePtr->hour same as ( *timePtr ).hour
Parentheses required
* lower precedence than .

7. union To store variable using the same space E.G.:
union {int a; char b[2];} d;
//low byte is stored first, low-indexed element is stored first
d.a=0x1234;
cout<<hex<<d.a<<endl; //1234
cout<<hex<<(int)d.b[0]<<endl; //34
cout<<hex<<(int)d.b[1]<<endl; //12
d.b[0]=0x56;
cout<<hex<<d.a<<endl; //5612

8. typedef for alias typedef char* string; string str=“abcde”;
string s[]={“abc”,”def”,”ghi”};
typedef unsigned char byte;
byte a[4],*p,c;
tyepdef struct {int a, int b} name;
name s1,s2;
typedef struct tagname {int a, int b} newname;
newname n1,n2;
tagname t;

9. The End