c_cpp

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1 C C++ C C++ C++ (object oriented) C C++.cpp C C++ C C++ : for (int i=0;i<max; i++) string[i]=string2[i]; : c=a+b; int x; x=a-b; 1

2 C++ cout cin C++ #include <iostream> C printf scanf #include <stdio.h> C++ #include <stdio.h> printf scanf C++ : cout C++ cout cout << << cout << value ; cout << x; cout << Value <<x; cout << Value << x << \n ; cout << Value << x << \n ; cout << Value <<xx <<endl // endl 2

3 C++ : cin C++ cin cin >> >> cin >> answer; cin.getline(, ) cin.getline(str,80) ch=cin.get(); Namespace Namespace using C++ std namespace #include <iostream> using namespace std; 3

4 cin cout C C++ int, float, double, char signed, unsigned, long, short, const, volitale, static, register, extern C++ public, private, protected, friend, inline, virtual unsigned a unsigned int a short a short int a; long a long int a; 4

5 :: C (global variable) (local variable) C++ :: :: C++ :: :: :: ex1_1 int i=10; void main(){ int i=20; { cout<<"the inner block\n"; int n=i++; int i=30; ::i++; cout << i= <<i<< ::i= <<::i<<endl; cout << n= <<n<<endl; cout <<"The outer block\n"; cout << i= <<i<< ::i= <<::i<<endl; 5

6 : const const #define #define const const : const float pi= ; // #define pi // const int *p; (*p)++; : void a (const int *p) 6

7 ( ) C++ (reference) type & identifier1=identifier2; identifier1 identifier2 : int a,b; int &alt=a; // alt a alt=b; // a=b alt++; // a++ ( ) int a; int *point=&a; *point=a point=&a *point++; // a++ a++; // *point++; 7

8 char & refchar= \0 ; char temp= \0 ; char &refchar=temp; C (call by value) C & * C++ 8

9 : ex1_2 void Swap(int *p, int *q){ int temp; temp=*p; *p=*q; *q=temp; void main(){ int a,b; cout << a= ; cin >> a; cout << b= ; cin >> b; Swap(&a,&b); cout << a= <<a<<endl; cout << b= <<b<<endl; : ex1_3 void Swap(int &p, int &q){ int temp; temp=p; p=q; q=temp; cout << a= ; cin >> a; cout << b= ; cin >> b; Swap(a,b); cout << a= <<a<<endl; cout << b= <<b<<endl; void main(){ int a,b; 9

10 C++ : void abc(float k, int j, int i=5) // void xyz(float k=1,int j, int i) // void err_use(float k, int j=2, int i) // abc(5,3) abc(2,4,1) ex1_4 int add(int i,int j=1){ return(i+j); void main(){ int a; cout <<"a="; cin >> a; cout << add(a,2) << endl; //, a 2 cout << add(a) << endl; // 1, a 1 ( ) 10

11 inline C/C++ #define : #define sq(x) x*x #define C/C++ :(ex1_5) #define sq(x) x*x void main(){ int y=5; cout <<sq(y)<< \n ; // 25 cout <<sq(y+1)<< \n ; // 11, 5*1+5*1=11 inline #define C++ inline inline ( ) { // C++ inline inline : : 11

12 inline ex1_6 inline int SQ(int x){return (x*x); void main(){ int a=5,b=3; cout << SQ(a-b)= <<SQ(a-b); SQ(a-b)=4 C malloc, calloc, realloc( ), free #include <alloc.h> C++ new delete 12

13 new new : : = new ; float *buf; buf=new float; // 1 : = new [ ] ; int *p; p=new int[20]; // 20 delete delete new : : delete ; float *buf; buf=new float; // 1 : delete [] ; int *p; p=new int[20]; // 20 13

14 new malloc malloc new ( int, char, double, float) malloc free C (constructor ) (destructor) new delete C++ (constructor ) (destructor) new delete new delete ex1_7 #include <alloc.h> class a{ public: a(){ cout << "constructor by new\n ; ~a() {cout << "destructor by delete\n"; ; class b{ public: b(){ cout << "constructor by malloc\n"; ; void main(){ a *p; b *q; p=new a[3]; // 3 a q=(b *)malloc(sizeof(b)); // constructor delete [] p; free(q); constructor by new constructor by new constructor by new destructor by delete destructor by delete destructor by delete 14

15 C (global variable) (static variable) (local variable) ex1_8 void a(){ static c=0; c++; cout<<c<<endl; void main(){ a(); // 1 a(); // 2 15

16 C++ struct Stock { char type; double netto; static int count; ; Stock sk1,sk2; sk1.count sk2.count :: type :: public :: private public 16

17 ( ) a ctest ~ctest(){ 0 constructor 1 destructor 1 (ex1_9) class ctest{ private: static int a; public: ctest(){ a++; a--; void showa(){ cout << a <<endl; ; int ctest::a=0; void main() { ctest c1; c1.showa(); ctest c2; c2.showa(); /* 1 */ /* 2 */ ( ) ex1_10 class ptest{ private: static int a; public: float b; static int d; static void c(){ cout << here ; ; int ptest::d=0; int ptest::a=0; void main(){ ptest p,q; cout<< Size of class ptest= <<sizeof(ptest) << \n ; cout << start address of p= <<&p<< \n ; cout << address of p.b= <<&p.b<< \n ; cout << \ntest of static variable\n ; cout << address of ptest::d << \n ; cout << address of p.d= <<&p.d<< \n ; cout << address of q.d= <<&q.d<< \n ; cout << \nfunction in class\n ; cout << address of function c by &ptest::c= << &ptest::c<< \n ; cout << adress of function c by ptest::c= <<ptest::c<< \n ; cout << address of function p.c= <<p.c<< \n ; 17

18 cout << address of function q.c= <<q.c<< \n ; Size of class ptest=4 start address of p=0x1a130ffc address of p.b=0x1a130ffc Test of static variable address of ptest::d address of p.d=0x address of q.d=0x function in class address of function c by &ptest::c=0x e address of function c by ptest::c=0x e address of function p.c=0x e address of function q.c=0x e this : static ( ) 18

19 C++ : C (type) expression : y=(double)x; // x double y : type(expression) : y=double(x); // x double y static_cast static_cast<type to convert to>(object to convert) int z = 3; float x = static_cast<int>(z); dynamic_cast 19

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FY.DOC 高职高专 21 世纪规划教材 C++ 程序设计邓振杰主编贾振华孟庆敏副主编人民邮电出版社内容提要本书系统地介绍 C++ 语言的基本概念基本语法和编程方法, 深入浅出地讲述 C++ 语言面向对象的重要特征 : 类和对象抽象封装继承等主