为提高我们的程序品质特将林博士的资料作为我公司程序员的学习教材，请各位读读，我把我的看法用红字表出，供大家探讨

Transcription

1 C++/C [ ] [] [ ] / V V V

2 Windows Unix if for switch goto const #define

3 free delete malloc/free new/delete malloc/free new/delete C

4 9.4 String String const A C++/C 114 B C++/C 119 C C++/C 125 C++/C N-1

5 Internet (1) (2) (3) (4) (5) (6) (7) (8) (9) 30 (10) 9:00 5:00 9: C++/C CAD 3D

6 C++ 3D 3D strcpy IT

7 IT if 14 C++/C IT 1

8 B C++/C C++/C 4 C++/C

9 Bug CMMI CMMI C++/C CMMI

10 C++/C implemen definition C++/C.h C.c C++.cpp.cc / 4 /* * Copyright (c) 2001, * All rights reserved. * * filename.h * *

11 * * 1.1 * * * * 1.0 * * */ graphics.h ifndef/define/endif #include <filename.h> #include filename.h

12 1-2-1 C extern int value #include myheader.h // 1-1 #ifndef GRAPHICS_H // graphics.h #define GRAPHICS_H #include <math.h> // #include myheader.h // void Function1(); // class Box // ; #endif 1-2 C++/C

13 graphics.cpp 1-3 // 1-1 #include graphics.h // // void Function1() // void Box::Draw()

14 1-3 C++/C 1.4 BasicFortran C++/C include source INCLUDE API SRC DOC TEST INCLUDE SRC SRC

15 a b // void Function1() // void Function2() // while (condition) statement1; // if (condition) statement2;

16 // void Function3() else statement3; // statement4; 2-1(a) 2-1(b) ifforwhiledo 2-2a 2-2b int width; int height; int depth; x = a + b; y = c + d; // // // int width, height, depth; // X a + b; y = c + d; z = e + f;

17 z = e + f; if (width < height) if (width < height) dosomething(); dosomething(); for (initialization; condition; update) for (initialization; condition; update) dosomething(); dosomething(); other(); // other(); 2-2(a) 2-2(b) int width = 10; // width int height = 10; // height int depth = 10; // depth constvirtualinlinecase ifforwhile

18 ; Function(x, y, z); for (initialization; condition; update) =+= >= <=+ *%&& <<, ^ 2-3-6!~ > for if for (i=0; i<10; i++)if ((a<=b) && (c<=d)) void Func1(int x, int y, int z); // void func( int x, int y, int z ); // void Func1 (int x,int y,int z); if (year >= 2000) // // if(year>=2000) // if ((a>=b) && (c<=d)) // if(a>=b&&c<=d) for (i=0; i<10; i++) // // for( I=0; I<10; I++ ) // for(i=0;i<10;i++) // for (i = 0; i < 10; i ++) x = a < b? a : b; // // x=a<b?a:b; int *x = &y; // // int * x = & y; //

19 array[5] = 0; // array [ 5 ] = 0; a.function(); b->function(); // a. Function(); // b -> Function(); a 2-4b void Function(int x) // program code if (condition) // program code else void Function(int x) // program code // if (condition) // program code else // program code //

20 // program code for (initialization; condition; update) for (initialization; condition; update) // program code // program code While (condition) while (condition) // program code // program code 2-4(a) 2-4(b)

21 2-5-2 if ((very_longer_variable1 >= very_longer_variable12) && (very_longer_variable3 <= very_longer_variable14) && (very_longer_variable5 <= very_longer_variable16)) dosomething(); virtual CMatrix CMultiplyMatrix (CMatrix leftmatrix, CMatrix rightmatrix); for (very_longer_initialization; very_longer_condition; very_longer_update) dosomething(); * * int* x; x int int* y x, y; x y

22 2-6-1 * char *name; int *x, y; // y 2.7 C /* */ C++/* // i++; // i

23 2-7-8 /* * * * * */ if () while () void Function(float x, float y, float z) // end of while // end of if publicprotectedprivate 1 private public 8-3 a

24 2 public private 8.3 b C++ Biarne Stroustrup class A private: int i, j; float x, y; public: void Func1(void); void Func2(void); class A public: void Func1(void); void Func2(void); private: int i, j; float x, y; 8.3(a) 8.3(b)

25 3 Microsoft ch p ppch int i, j, k; float x, y, z; int ii, ij, ik; // i int float fx, fy, fz; // f float CurrentValue NowValue

26 3-1-2 min-length && max-information ANSI C 6 C++/C! maxval maxvalueuntiloverflow i,j,k,m,n,x,y,z Windows AddChild Unix add_child int x, X; // x X void foo(int x); // foo FOO void FOO(float x); float value; float oldvalue; float newvalue;

27 3-1-7 DrawBox(); // box->draw(); // int int minvalue; maxvalue; int int SetValue(); GetValue(); Value1,Value2 3.2 Windows Windows class Node; //

28 class LeafNode; void Draw(void); // // void SetValue(int value); // BOOL flag; int drawmode; const int MAX = 100; const int MAX_LENGTH = 100; s_ static void Init() static int s_initvalue; // g_ global

29 int g_howmanypeople; // int g_howmuchmoney; // m_ member void Object::SetValue(int width, int height) m_width = width; m_height = height; OpenGL gl GL 3.3 Unix 4 ifforwhilegotoswitch C++/C 4.1

30 C++/C * ( ) [ ] ->.! ~ sizeof + - * & * / % + - << >> < <= > >= ==!= & ^ &&?: = += -= *= /= %= &= ^= = <<= >>= word = (high << 8) low if ((a b) && (a & c))

31 4.2 a = b = c = i = a >= b && c < d && c + f <= g + h ; // d = (a = b + c) + r ; a d a = b + c; d = a + r; if (a < b < c) // a < b < c if ((a<b) && (b<c)) if ( (a<b)<c ) 4.3 if

32 if C++/C if TRUEFALSE 10 FALSE TRUE TRUE Visual C++ TRUE 1Visual Basic TRUE -1 flag if if (flag) // flag if (!flag) // flag if (flag == TRUE) if (flag == 1 ) if (flag == FALSE) if (flag == 0) === 0 value if if (value == 0) if (value!= 0) if (value) // value if (!value)

33 === float double === x if (x == 0.0) // if ((x>=-epsinon) && (x<=epsinon)) EPSINON === NULL NULL 0 p if if (p == NULL) // p NULL p if (p!= NULL) if (p == 0) // p if (p!= 0) if (p) // p if (!p) if

34 if (NULL == p) if (p == NULL) if (p = pnull) NULL if (p = NULL) if (NULL NULL = p) if/else/return if (condition) return x; return y; if (condition) return x; else return y; return (condition? x : y); 4.4 C++/C for while do CPU 4-4(b) 4-4(a)

35 for (row=0; row<100; row++) for (col=0; col<5; col++ ) for ( col=0; col<5; col++ ) for (row=0; row<100; row++) sum = sum + a[row][col]; sum = sum + a[row][col]; 4-4(a) 4-4(b) (c) 4-4(d) N-1 N 4-4(d) N 4-4(c) for (i=0; i<n; i++) if (condition) if (condition) for (i=0; i<n; i++) DoSomething(); DoSomething(); else DoOtherthing(); else for (i=0; i<n; i++)

36 DoOtherthing(); 4-4(c) 4-4(d) 4.5 for for for for 4-5(a) x 0 =< x < N N 4-5(b) x 0 =< x <= N-1 N 4-5(a) for (int x=0; x<n; x++) for (int x=0; x<=n-1; x++) 4-5(a) 4-5(b) 4.6 switch if switch switch if if switch switch switch (variable)

37 case value1 : break; case value2 : break; default : break; case break default default default : break; default 4.7 goto goto goto goto goto state; String s1, s2; // goto int sum = 0; // goto state:

38 goto C++/C goto goto goto break ; goto error; error: goto goto,, GOTO 5 C #define C++ #define const const 5.1

39 #define MAX 100 /* C */ const int MAX = 100; // C++ const const float PI = ; // C++ const 5.2 const #define C++ const #define 1 const 2 const C++ const const

40 const float RADIUS = 100; const float DIAMETER = RADIUS * 2; 5.4 #define const const const const const SIZE class A const int SIZE = 100; // const int array[size]; // SIZE ; const class A A(int size); // const int SIZE ; ; A::A(int size) : SIZE(size) //

41 A A a(100); // a SIZE 100 b(200); // b SIZE 200 const class A ; enum SIZE1 = 100, SIZE2 = 200; // int array1[size1]; int array2[size2]; PI= C++/C C pass by valuepass C++ by pointer pass by reference 6.6

42 void void SetValue(int width, int height); // void SetValue(int, int); // float GetValue(void); // float GetValue(); // StringCopy str1 str2 void StringCopy(char *str1, char *str2); str1 str2 strsource strdestination strsource strdestination void StringCopy(char *strsource, char *strdestination); char str[20]; StringCopy(str, Hello World); //

43 6-1-3 const void StringCopy(char *strdestinationconst char *strsource); C printf int printf(const chat *format[, argument]); C void C++ C C++/ C void C getchar char c;

44 c = getchar(); if (c == EOF) getchar c char getchar char int int getchar(void); c char [ ] EOF char if getchar return C getchar int getchar getchar EOF 1 getchar int return getchar BOOL GetChar(char *c); gechar GetChar putchar(getchar()); getchar strcpy char *strcpy(char *strdestconst char *strsrc); strcpy strsrc strdest strdest

45 char str[20]; int length = strlen( strcpy(str, Hello World) ); class String // String & operate=(const String &other); // friend friend String operate+( const String &s1, const String &s2); private: char *m_data; String operate = String & String::operate=(const String &other) if (this == &other) return *this; delete m_data; m_data = new char[strlen(other.data)+1]; strcpy(m_data, other.data);

46 return *this; // *this String return *this String a,b,c; a = b; // *this a = b = c; // *this String operate + String operate+(const String &s1, const String &s2) String temp; delete temp.data; // temp.data 0 temp.data = new char[strlen(s1.data) + strlen(s2.data) +1]; strcpy(temp.data, s1.data); strcat(temp.data, s2.data); return temp; String temp temp

47 c = a + b; a + b c return return return return 1return char * Func(void) char str[] = hello world; // str return str; // 2 3 return

48 return String(s1 + s2); temp String temp(s1 + s2); return temp; temp temp temp return int(x + y); // int temp = x + y; return temp; int,float,double C/C++ static static

49 6.5 Debug Release Debug Release assert Debug 6-5 assert assert void *memcpy(void *pvto, const void *pvfrom, size_t size) assert((pvto!= NULL) && (pvfrom!= NULL)); // byte *pbto = (byte *) pvto; // pvto byte *pbfrom = (byte *) pvfrom; // pvfrom while(size -- > 0 ) *pbto ++ = *pbfrom ++ ; return pvto; 6-5 assert Debug Release assert assert assert assert assert assert

50 [Maguire, p8-p30] C++ m referencem referent int m; int &n = m; n m n m n m m n m 1 2 NULL NULL 3 k i k = j k j k 6 k i i 6 int i = 5; int j = 6;

51 int &k = i; k = j; // k i 6; C++ Func1 x n x n, n 0 void Func1(int x) x = x + 10; int n = 0; Func1(n); cout << n = << n << endl; // n = 0 Func2 x n n n 10 void Func2(int *x) (* x) = (* x) + 10; int n = 0; Func2(&n);

52 cout << n = << n << endl; // n = 10 Func3 x n x n x n n 10 void Func3(int &x) x = x + 10; int n = 0; Func3(n); cout << n = << n << endl; // n = 10 7 Bill Gates 640K ought to be enough for everybody

53 Bill Gates static 2 3 malloc new free delete 7.2 NULL p assert(p!=null) malloc new if(p==null) if(p!=null)

54 1 1 for malloc free new/delete 1 2 return 3 free delete NULL malloc new NULL NULL

55 free delete NULL 7.3 C++/C a 6 hello 0a a[0]= X p world world 0 p[0]= X char a[] = hello; a[0] = X; cout << a << endl; char *p = world; // p p[0] = X; // cout << p << endl; 7-3-1

56 a b b = a strcpy b a if(b==a) strcmp p = a a p a p a malloc p strlen(a)+1 strcpy if(p==a) strcmp // char a[] = "hello"; char b[10]; strcpy(b, a); // b = a; if(strcmp(b, a) == 0) // if (b == a) // int len = strlen(a); char *p = (char *)malloc(sizeof(char)*(len+1)); strcpy(p,a); // p = a; if(strcmp(p, a) == 0) // if (p == a)

57 sizeof 7-3-3a sizeof(a) 12 0 p a sizeof(p) 4 sizeof(p) sizeof(char*) p C++/C b a sizeof(a) sizeof(char *) char a[] = "hello world"; char *p = a; cout<< sizeof(a) << endl; // 12 cout<< sizeof(p) << endl; // a void Func(char a[100]) cout<< sizeof(a) << endl; // b Test GetMemory(str, 200) str str NULL void GetMemory(char *p, int num)

58 p = (char *)malloc(sizeof(char) * num); void Test(void) char *str = NULL; GetMemory(str, 100); // str NULL strcpy(str, "hello"); // GetMemory p _p _p = p p _p _p p GetMemory GetMemory free void GetMemory2(char **p, int num) *p = (char *)malloc(sizeof(char) * num); void Test2(void) char *str = NULL; GetMemory2(&str, 100); // &str

59 strcpy(str, "hello"); cout<< str << endl; free(str); char *GetMemory3(int num) char *p = (char *)malloc(sizeof(char) * num); return p; void Test3(void) char *str = NULL; str = GetMemory3(100); strcpy(str, "hello"); cout<< str << endl; free(str); 7-4-3

60 return return char *GetString(void) char p[] = "hello world"; return p; // void Test4(void) char *str = NULL; str = GetString(); // str cout<< str << endl; return Test4 str = GetString str NULL str hello world char *GetString2(void) char *p = "hello world"; return p;

61 void Test5(void) char *str = NULL; str = GetString2(); cout<< str << endl; return Test5 GetString2 GetString2 hello world GetString2 7.5 free delete free delete delete 7-5 p free NULL p p NULL p p p if (p!= NULL) if p NULL char *p = (char *) malloc(100); strcpy(p, hello); free(p); // p p

62 if(p!= NULL) // strcpy(p, world); // 7-5 p p void Func(void) char *p = (char *) malloc(100); // NULL NULL

63 7.7 NULL NULL if 1 NULL NULL char *p = NULL; char *str = (char *) malloc(100); 2 p free delete NULL p class A public: void Func(void) cout << Func of class A << endl; ; void Test(void) A *p; A a; p = &a; // a

64 p->func(); // p Test p->func() a p a p 7.8 malloc/free new/delete malloc free C++/C new/delete C++ maloc/free malloc/free malloc/free C++ new delete new/delete malloc/free new/delete 7-8 class Obj public : Obj(void) cout << Initialization << endl; ~Obj(void) cout << Destroy << endl; void Initialize(void) cout << Initialization << endl; void Destroy(void) cout << Destroy << endl; ;

65 void UseMallocFree(void) Obj *a = (obj *)malloc(sizeof(obj)); // a->initialize(); // // a->destroy(); // free(a); // void UseNewDelete(void) Obj *a = new Obj; // // delete a; // 7-8 malloc/free new/delete Obj Initialize Destroy UseMallocFree malloc/free Initialize Destroy UseNewDelete malloc/free new/delete malloc/free new/delete new/delete malloc/free C++ malloc/free C++ C C malloc/free

66 free new delete malloc new/delete malloc/free 7.9 malloc new NULL 1 NULL return void Func(void) A *a = new A; if(a == NULL) return; 2 NULL exit(1) void Func(void) A *a = new A; if(a == NULL) cout << Memory Exhausted << endl;

67 exit(1); 3 new malloc Visual C++ _set_new_hander new malloc new C exit(1) exit(1) 32 malloc new Windows 98 Visual C Window Unix Windows void main(void)

68 float *p = NULL; while(true) p = new float[ ]; cout << eat memory << endl; if(p==null) exit(1); malloc/free malloc void * malloc(size_t size); malloc length int *p = (int *) malloc(sizeof(int) * length); u malloc void * malloc void * u malloc int, float int float cout << sizeof(char) << endl; cout << sizeof(int) << endl; cout << sizeof(unsigned int) << endl;

69 cout << sizeof(long) << endl; cout << sizeof(unsigned long) << endl; cout << sizeof(float) << endl; cout << sizeof(double) << endl; cout << sizeof(void *) << endl; malloc () sizeof p = malloc(sizeof(p)) u free void free( void * memblock ); free malloc p free(p) p NULL free p p NULL free p UNIX malloc /* coremap swapmap COREMAP 64BYTE SWAPMAP 512BYTE 4KBYTE */ struct map char *m_size; char *m_addr;

70 malloc( struct map *mp, int size ) register int a; register struct map *bp; for( bp = mp; bp->m_size; bp++ ) if( bp->m_size >= size ) a = bp->m_addr; bp->m_addr += size; if(( bp->m_size =- size ) == 0 ) do bp++; (bp 1)->m_addr = bp->m_addr while(( bp-1)->m_size = bp->m_size ); return(a); return( 0 ); 7.11 new/delete new malloc int *p1 = (int *)malloc(sizeof(int) * length); int *p2 = new int[length];

71 new sizeof new new class Obj public : Obj(void); Obj(int x); // // void Test(void) Obj *a = new Obj; Obj *b = new Obj(1); // 1 delete a; delete b; new Obj *objects = new Obj[100]; // 100 Obj *objects = new Obj[100](1);// delete [] delete []objects; // delete objects; //

72 delete objects[0] C++/C C 1 C C++ C C++overloadedinline const virtual virtual C C++ C EatBeef,EatFish,EatChicken Eat

73 void EatBeef(); // void Eat(Beef ); void EatFish(); // void Eat(Fish ); void EatChicken(); // void Eat(Chicken ); Eat C void Function(void); int Function (void); int int x = Function (); Function C++/C Function Eat _eat_beef_eat_fish_eat_chicken

74 C++ C C void foo(int x, int y); C _foo C++_foo_int_int C C++ C externc extern C void foo(int x, int y); // extern C #include myheader.h // C C++ foo C _foo _foo_int_intc++ C externc include void Print(); //

75 class A void Print(); // Print Print :: ::Print(); // Print output int output float output(0.5) int float # include <iostream.h> void output( int x); // void output( float x); // void output( int x) cout << " output int " << x << endl ; void output( float x)

76 cout << " output float " << x << endl ; void main(void) int x = 1; float y = 1.0; output(x); // output int 1 output(y); // output float 1 output(1); // output int 1 // output(0.5); // error! ambiguous call, output(int(0.5)); // output int 0 output(float(0.5)); // output float override C

77 virtual virtual Base::f(int)Base::f(float) Base::g(void) Derived::g(void) #include <iostream.h> class Base public: void f(int x) cout << "Base::f(int) " << x << endl; void f(float x) cout << "Base::f(float) " << x << endl; virtual void g(void) cout << "Base::g(void)" << endl; ; public: class Derived : public Base

78 virtual void g(void) cout << "Derived::g(void)" << endl; ; void main(void) Derived d; Base *pb = &d; pb->f(42); // Base::f(int) 42 pb->f(3.14f); // Base::f(float) 3.14 pb->g(); // Derived::g(void) C++ 1 virtual 2 virtual 8-2-2a 1 Derived::f(float) Base::f(float) 2 Derived::g(int) Base::g(float) 3 Derived::h(float) Base::h(float)

79 #include <iostream.h> class Base public: virtual void f(float x) cout << "Base::f(float) " << x << endl; void g(float x) cout << "Base::g(float) " << x << endl; void h(float x) cout << "Base::h(float) " << x << endl; ; class Derived : public Base public: virtual void f(float x) cout << "Derived::f(float) " << x << endl; void g(int x) cout << "Derived::g(int) " << x << endl; void h(float x) cout << "Derived::h(float) " << x << endl; ; 8-2-2a C bbp dp void main(void)

80 Derived d; Base *pb = &d; Derived *pd = &d; // Good : behavior depends solely on type of the object pb->f(3.14f); // Derived::f(float) 3.14 pd->f(3.14f); // Derived::f(float) 3.14 // Bad : behavior depends on type of the pointer pb->g(3.14f); // Base::g(float) 3.14 pd->g(3.14f); // Derived::g(int) 3 (surprise!) // Bad : behavior depends on type of the pointer pb->h(3.14f); // Base::h(float) 3.14 (surprise!) pd->h(3.14f); // Derived::h(float) b pd->f(10) Base::f(int) Base::f(int) Derived::f(char *) 10 class Base public:

81 void f(int x); ; class Derived : public Base public: void f(char *str); ; void Test(void) Derived *pd = new Derived; pd->f(10); // error pd->f(10) Derived::f(char *) Derived f pd->f(10) f pd->f(10) Base::f(int) Derived class Derived : public Base public:

82 void f(char *str); void f(int x) Base::f(x); ; void Foo(int x=0, int y=0); // void Foo(int x=0, int y=0) // void Foo(int x, int y=0, int z=0); void Foo(int x=0, int y, int z=0);

83 8-3-2 output #include <iostream.h> void output( int x); void output( int x, float y=0.0); void output( int x) cout << " output int " << x << endl ; void output( int x, float y) cout << " output int " << x << " and float " << y << endl ; void main(void) int x=1; float y=0.5; // output(x); // error! ambiguous call output(x,y); // output int 1 and float 0.5

84 C++ operator Complex Add(const Complex &a, const Complex &b); Complex operator +(const Complex &a, const Complex &b); Complex a, b, c; c = Add(a, b); // c = a + b; // + p44-p47] = () [] ->

85 += -= /= *= &= = ~= %= >>= <<= C C++ 1 C++ int,float C++#,@,$ C++ C CALL return #define MAX(a, b) (a) > (b)? (a) : (b)

86 result = MAX(i, j) + 2 ; result = (i) > (j)? (i) : (j) + 2 ; +: result = ( (i) > (j)? (i) : (j) ) + 2 ; #define MAX(a, b) ( (a) > (b)? (a) : (b) ) result = MAX(i++, j); result = (i++) > (j)? (i++) : (j); C++ C++ C++ C++ assert assert Debug Debug Release assert assert Debug Release assert

87 inline inline Foo inline void Foo(int x, int y); // inline void Foo(int x, int y) Foo void Foo(int x, int y); inline void Foo(int x, int y) // inline inline inline inline C++/C class A public: void Foo(int x, int y) //

88 // class A public: void Foo(int x, int y) // inline void A::Foo(int x, int y) inline

89 8.6 C++ C++ 9 A C++ A A(void); A(const A &a); ~A(void); A & operate =(const A &a); // // // // 1 C++ Stroustrup 2 C++

90 String class String public: String(const char *str = NULL); // String(const String &other); // ~ String(void); // String & operate =(const String &other); // private: char *m_data; // ; 9.1 C C++ Stroustrup C++ Stroustrup ~ void

91 9.2 class A A(int x); // A ; class B : public A B(int x, int y);// B ; B::B(int x, int y) : A(x) // A const 5.4 u

92 class A A(void); // A(const A &other); // A & operate =( const A &other); // class B public: B(const A &a); // B private: A m_a; // ; 9-2(a) B A m_a 9-2 (b) B m_a B m_a A A a m_a B::B(const A &a) B::B(const A &a) : m_a(a)

93 m_a = a; 9-2(a) 9-2(b) F class F public: F(int x, int y); // private: int m_x, m_y; int m_i, m_j; 9-2(c)F 9-2(d)F F::F(int x, int y) F::F(int x, int y) : m_x(x), m_y(y) m_x = x; m_i = 0; m_y = y; m_j = 0; m_i = 0; m_j = 0;

94 9-2(c) 9-2(d) 9.3 [Eckel, p String // String String::String(const char *str) if(str==null) m_data = new char[1]; *m_data = 0; else int length = strlen(str); m_data = new char[length+1]; strcpy(m_data, str);

95 // String String::~String(void) delete [] m_data; // m_data delete m_data; 9.5 u String a,b a.m_data hello b.m_data world a b b.m_data = a.m_data b.m_data b.m_data a.m_data a b m_data u String a(hello); String b(world); String c = a; // c(a); c = b; //

96 String c(a) 9.6 String // String::String(const String &other) // other m_data int length = strlen(other.m_data); m_data = new char[length+1]; strcpy(m_data, other.m_data); // String & String::operate =(const String &other) // (1) if(this == &other) return *this; // (2) delete [] m_data; // 3 int length = strlen(other.m_data);

97 m_data = new char[length+1]; strcpy(m_data, other.m_data); // 4 return *this; String 9.4 NULL NULL String 1 // // b = a; b = &a; c = b; a = *b; a = c; delete if if(this == &other)

98 if( *this == other) 2 delete 3 strlen 0 strcpy 0 4 return *this return this return other other other return other 9.7 class A private: A(const A &a); // A & operate =(const A &a); // ; A b(a); // b = a; //

99 A 9.8 virtual #include <iostream.h> class Base ; public: virtual ~Base() cout<< "~Base" << endl ; class Derived : public Base public: virtual ~Derived() cout<< "~Derived" << endl ; ; void main(void) Base * pb = new Derived; // upcast delete pb;

100 ~Derived ~Base ~Base class Base public: Base & operate =(const Base &other); // Base private: int m_i, m_j, m_k; ; class Derived : public Base public: Derived & operate =(const Derived &other); // Derived private: int m_x, m_y, m_z;

101 ; Derived & Derived::operate =(const Derived &other) //1 if(this == &other) return *this; //2 Base::operate =(other); // //3 m_x = other.m_x; m_y = other.m_y; m_z = other.m_z; //4 return *this; 9.9 C++

102 Big-Three[Cline] [Meyers] [M 10 ObjectClassInstance C++ InheritanceComposition COM CORBA C++ COM CORBA 10.1 A B A B A public: class A void void Func1(void); Func2(void); ; class B : public A

103 public: void Func3(void); void Func4(void); ; main() B b; b.func1(); // B A Func1 b.func2(); // B A Func2 b.func3(); b.func4(); C A B B B A B A a kind of B A ManHuman Man Human Boy Man class Human

104 ; class Man : public Human ; class Boy : public Man ; OstrichBird Bird Ostrich::Fly class Bird public: virtual void Fly(void); ; class Ostrich : public Bird

105 ; CircleEllipse Ellipse B A A B B A A B a part of B A A B EyeNoseMouthEar Head EyeNoseMouthEar class Eye class Nose public: public: void Look(void); void Smell(void); ; class Mouth ; class Ear public: public: void Eat(void); void Listen(void); ; ; // class Head

106 public: void Look(void) m_eye.look(); void Smell(void) m_nose.smell(); void Eat(void) m_mouth.eat(); void Listen(void) m_ear.listen(); private: Eye Nose Mouth Ear m_eye; m_nose; m_mouth; m_ear; ; Head EyeNoseMouthEar Head Eye Nose Mouth Ear Head LookSmell EatListen // class Head : public Eye, public Nose, public Mouth, public Ear ; Head EyeNoseMouthEar

107 const const C++ const const const constant const C++ const whenever you need const const const const StringCopy void StringCopy(char *strdestination, const char *strsource); strsource strdestination strsource const strsource

108 const void Func1(int x) void Func1(const int x) void Func2(A a) void Func2(const A a) A void Func(A a) A a void Func(A &a) void Func(A &a) a const void Func(const A &a) void Func(int x) void Func(const int &x) const & const void Func(A a) void Func(const A &a) void Func(int x) void Func(const int &x) const & const const const

109 const char * GetString(void); char *str = GetString(); const char *str = GetString(); const int GetInt(void) const int GetInt(void) A GetA(void) const A GetA(void) A A GetA(void) const A & GetA(void) 6.2 class A A & operate = (const A &other); // ; A a, b, c; // a, b, c A a = b = c; // (a = b) = c; //

110 const a = b = c (a = b) = c const const const const stack GetCount GetCount const GetCount class Stack public: void int Push(int elem); Pop(void); int GetCount(void) const; // const private: int int m_num; m_data[100]; ; int Stack::GetCount(void) const ++ m_num; // m_num Pop(); // const return m_num;

111 const const

112 &&<= >= I/O

113 PC-LintLogiScope [Cline] Marshall P. Cline and Greg A. Lomow, C++ FAQs, Addison-Wesley, 1995 [Eckel] Bruce Eckel, Thinking in C++C [Maguire] Steve Maguire, Writing Clean Code 1993 [Meyers] Scott Meyers, Effective C++, Addison-Wesley, 1992 [Murry] Robert B. Murry, C++ Strategies and Tactics, Addison-Wesley, 1993 [Summit] Steve Summit, C Programming FAQs, Addison-Wesley, 1996

114 A C++/C ifndef/define/endif? Ifforwhiledo * public, protected, private min-length && max-information

115 if? 1 TRUEFALSE 10 2== = 3=== NULL Case break switch default goto? C++ const const const

116 return assert assert return const const Use const whenever you need malloc new NULL 1 2 free delete NULL malloc/free new/delete malloc new/delete

117 C++ C *this virtual 4

118 1 B A A B B A 2 A B a part of B A A B

119 I/O B C++/C C++/C C++/C C++/C 90 BOOL, float, if 0, 0.0, FALSE n int if if ( n == 0 ) if ( n!= 0 )

120 BOOL flag if float x if char *p if Windows NT 32 C++ sizeof 10 char str[] = Hello ; char *p = str ; int n = 10; sizeof (str ) = void Func ( char str[100]) sizeof( str ) = sizeof ( p ) = sizeof ( n ) = void *p = malloc( 100 ); sizeof ( p ) =

121 25 1 ifndef/define/endif 2#include <filename.h> #include filename.h 3const 4 C++ C extern 5 for // for (i=0; i<n; i++) // if (condition)

122 if (condition) DoSomething(); else DoOtherthing(); for (i=0; i<n; i++) DoSomething(); else for (i=0; i<n; i++) DoOtherthing(); 20 void GetMemory(char *p) p = (char *)malloc(100); char *GetMemory(void) char p[] = "hello world"; return p;

123 void Test(void) char *str = NULL; GetMemory(str); strcpy(str, "hello world"); printf(str); void Test(void) char *str = NULL; str = GetMemory(); printf(str); Test Test Void GetMemory2(char **p, int num) *p = (char *)malloc(num); void Test(void) char *str = NULL; GetMemory(&str, 100); strcpy(str, "hello"); void Test(void) char *str = (char *) malloc(100); strcpy(str, hello); free(str); if(str!= NULL) strcpy(str, world); printf(str);

124 printf(str); Test Test strcpy 10 strcpy char *strcpy(char *strdest, const char *strsrc); strdest strsrc 1 C++/C strcpy

125 2strcpy strsrc strdest char * 25 String String class String public: String(const char *str = NULL); String(const String &other); // // ~ String(void); // String & operate =(const String &other); // private: char *m_data; // ; String 4 C C++/C BOOL, float, if

126 BOOL flag if 3 if ( flag ) if (flag == TRUE) if (!flag ) if (flag == 1 ) if (flag == FALSE) if (flag == 0) float x if 4 const float EPSINON = ; if ((x >= - EPSINON) && (x <= EPSINON) if (x == 0.0) === if (x!= 0.0) >=<= char *p if 3 if (p == NULL) if (p == 0) if (p!= NULL) if (p!= 0) if (p) if (!) Windows NT 32 C++ sizeof 10

127 char str[] = Hello ; char *p = str ; int n = 10; void Func ( char str[100]) sizeof( str ) = 4 2 sizeof (str ) = 6 2 sizeof ( p ) = 4 2 sizeof ( n ) = 4 2 void *p = malloc( 100 ); sizeof ( p ) = ifndef/define/endif 5 2#include <filename.h> #include filename.h 5 #include <filename.h> fil #include filename.h 3const 5 1 const 2const const

128 4 C++ C extern C 5 C++C C++ C void foo(int x, in C _foo C++ _foo_int_int C++ C externc 5 for 5 for (i=0; i<n; i++) if (condition) if (condition) for (i=0; i<n; i++) DoSomething(); DoSomething(); else DoOtherthing(); else for (i=0; i<n; i++) DoOtherthing(); N-1

129 5 20 void GetMemory(char *p) p = (char *)malloc(100); void Test(void) char *str = NULL; GetMemory(str); strcpy(str, "hello world"); printf(str); char *GetMemory(void) char p[] = "hello world"; return p; void Test(void) char *str = NULL; str = GetMemory(); printf(str); Test Test GetMemory GetMemory NULL Test str NULL strcpy(str, "hello world"); void GetMemory2(char **p, int num) void Test(void)

130 *p = (char *)malloc(num); void Test(void) char *str = NULL; GetMemory(&str, 100); strcpy(str, "hello"); printf(str); char *str = (char *) malloc(100); strcpy(str, hello); free(str); if(str!= NULL) strcpy(str, world); printf(str); Test Test 1 hello 2 free(str);str if(str!= NULL) strcpy 10 strcpy char *strcpy(char *strdest, const char *strsrc); strdest strsrc 1 C++/C strcpy char *strcpy(char *strdest, const char *strsrc);

131 assert((strdest!=null) && (strsrc!=null)); // 2 char *address = strdest; // 2 while( (*strdest++ = * strsrc++)!= 0 ) // 2 NULL ; return address ; // 2 2strcpy strsrc strdest char * // 2 int length = strlen( strcpy( strdest, hello world) ); 25 String String class String public: String(const char *str = NULL); String(const String &other); // // ~ String(void); // String & operate =(const String &other); // ; private: char *m_data; //

132 String 4 // String String::~String(void) // 3 delete [] m_data; // m_data delete m_data; // String String::String(const char *str) // 6 if(str==null) m_data = new char[1]; // NULL *m_data = 0 ; else int length = strlen(str); m_data = new char[length+1]; // NULL strcpy(m_data, str);

133 // String::String(const String &other) // 3 int length = strlen(other.m_data); m_data = new char[length+1]; // NULL strcpy(m_data, other.m_data); // String & String::operate =(const String &other) // 13 // (1) // 4 if(this == &other) return *this; // (2) // 3 delete [] m_data; // 3 // 3 int length = strlen(other.m_data); m_data = new char[length+1]; // NULL strcpy(m_data, other.m_data); // 4 // 3

134 return *this;