C++学习记录一

//////////////////////////////////////////////////////////////////////arrayone.cpp---small arrays of integers#include <iostream>int main1(){using namespace std;int yams[3];yams[0] = 7;yams[1] = 8;yams[2] = 6;int yamcosts[3] = {20,30,5};//yamcosts[3]= { 20, 30, 5 };这种初始化方式不行cout << "Total yams = " << yams[0] + yams[1] + yams[2] << endl;cout << "The package with " << yams[1] << " yams costs "<< yamcosts[1] << " cents per yam.\n";int total = yams[0] * yamcosts[0] + yams[1] * yamcosts[1];total = total + yams[2] * yamcosts[2];cout << "The total yam expense is " << total << " cents.\n";cout << "\nSize of yams array = " << sizeof yams << " bytes.\n";cout << "Size of one element = " << sizeof yams[0] << " bytes.\n";////////////////////////////////字符串拼接///////////////////////////cout << "I'd give my right arm to be" " a great violinist.\n";cout << "I'd give my right arm to be a great violinist.\n";cout << "I'd give my right ar""m to be a great violinist.\n";/////////////////////////////////////////////////////////////////////system("pause");return 0;}///////////////////////////////////////////////////////////////////////////程序清单4.2  string.cpp/////////////////////////////////////////////string.cpp---storing strings in an array#include <iostream>#include<cstring>int main2(){using namespace std;const int Size = 15;char name1[Size];char name2[Size] = "C++owboy";cout << "Howdy! I'm " << name2;cout << "! What's your name?\n";cin >> name1;cout << "Well," << name1 << ",your name has ";cout << strlen(name1) << " letters and is stored\n";cout << "in an array of " << sizeof (name1) << " bytes.\n";cout << "Your initial is " << name1[0] << ".\n";name2[3] = '\0';cout << "Here are the first 3 characters of my name: ";cout << name2 << endl;system("pause");return 0;}///////////////////////////////////////////////////////////////////////////////程序清单4.3///////////////////////////////////////////////////////////insert1.cpp----reading more than one string////////////////////////////////////////////////////////////////////////////////////////////////#include<iostream>int main3(){using namespace std;const int ArSize = 20;char name[ArSize];char dessert[ArSize];cout << "Enter your name:\n";cin >> name;cout << "Enter your favorite dessert:\n";cin >> dessert;cout << "I have some delicious " << dessert;cout << " for you," << name << ".\n";system("pause");return 0;}////////////////////////////////////////////////////////////////////程序清单4.4////////////////////////////////////////////////////insert2.cpp---reading more than one word with getline////////#include <iostream>int main4(){using namespace std;const int ArSize = 20;char name[ArSize];char dessert[ArSize];cout << "Enter your name:\n";cin.getline(name, ArSize);cout << "Enter your favorite dessert:\n";cin.getline(dessert, ArSize);cout << "I have some delicious " << dessert;cout << " for you," << name << ".\n";system("pause");return 0;}//////////////////////////////////////////////////////////////////////////程序清单4，5//////////////////////////////////////////////////insert3.cpp---reading more than one word with get() & get()////#include <iostream>int main5(){using namespace std;const int ArSize = 20;char name[ArSize];char dessert[ArSize];cout << "Enter your name:\n";cin.get(name, ArSize).get();//第二个get()将换行符读取掉，方便后面一行的读取。cout << "Enter your favorite dessert:\n";cin.get(dessert, ArSize).get();cout << "I have some delicious " << dessert;cout << " for you," << name << ",\n";system("pause");return 0;}///////////////////////////////////////////////////////////////////////////////////////程序清单4.6//////////////////////////////////////////////////////////////////numstr.cpp---following number input with line input///////////////////////#include <iostream>int main6(){using namespace std;cout << "What year was your house built?\n";int year;cin >> year;//cin.get();cout << "What is its street address？\n";char address[80];cin.getline(address, 80);cout << "Year built: " << year << endl;cout << "Address: " << address << endl;cout << "Done!\n";system("pause");return 0;}/////////////////////////////////////////////////////////////////////程序清单4.7///////////////////////////////////////////////////strtype1.cpp---using the C++ string class/////////////////#include <iostream>#include <string>int main7(){using namespace std;char charr1[20];char charr2[20] = "jaguar";string str1;string str2 = "panther";cout << "Enter a kind of feline: ";cin >> charr1;cout << "Enter another kind of feline: ";cin >> str1;cout << "Here are some felines:\n";cout << charr1 << " " << charr2 << " "<< str1 << " " << str2 << endl;cout << "The third letter in " << charr2 << " is"<< charr2[2] << endl;cout << "The third letter in " << str2 << " is"<< str2[2] << endl;system("pause");return 0;}//C++ 11字符串初始化//char first_date[] = { "Le Chapon Dodu" };//char second_date[] {"The Elegant Plate"};//string third_date = { "The Bread bowl" };//string fourth_date{ "Hank's Fine Eats" };//////////////////////////////////////////////////////////////////////////程序清单4.8///////////////////////////////////////////////////////strtype2.cpp---assigning,adding,and appending///////////////////#include <iostream>#include <string>int main8(){using namespace std;string s1 = "penguin";string s2, s3;cout << "You can assign one string object to another:s2=s1\n";s2 = s1;cout << "s1: " << s1 << ", s2: " << s2 << endl;cout << "You can assign a C-style string to a string object.\n";cout << "s2 = \"buzzard\"\n";s2 = "buzzard";cout << "s2: " << s2 << endl;cout << "You can concatenate strings: s3 = s1 + s2\n";s3 = s1 + s2;cout << "s1 += s2 yields s1 = " << s1 << endl;s2 += "for a day";cout << "s2 += \"for a day\"yields s2 =" << s2 << endl;system("pause");return 0;}////////////////////////////////////////////////////////////////////////////程序清单4.9////////////////////////////////////////////////////////////////strtype3.cpp----more string class feature///////////////////////////#include <iostream>#include <string>#include <cstring>int main(){using namespace std;char charr1[20];char charr2[20] = "jaguar";string str1;string str2 = "panther";str1 = str2;strcpy(charr1, charr2);str1 += str2;strcat(charr1, " juice");int len1 = str1.size();int len2 = strlen(charr1);cout << "The string " << str1 << " contains "<< len1 << " characters.\n";cout << "The string " << charr1 << " contains "<< len2 << " characters.\n";system("pause");return 0;}