c++primer plus 第4章编程练习之路

c++ Primer Plus（习题4.1）

#include<iostream>const int Lengh = 10;int main(){using namespace std;cout << "what is your frist name? ";char fristname[Lengh];cin.getline(fristname, Lengh);cout << "what is your last name?  ";char lastname[Lengh];cin.get(lastname, Lengh);cout << "what letter grade do you deserve?  ";char grade;cin >> grade;grade += 1;cout << "what is you age?  ";int years;                cin >> years;                          //要注意不能再cout那里改变字符的值，会按照编码值输出的cout << "Name: " << lastname << "," << fristname << endl;   cout << "Grade: " << grade << endl<< "Age: " << years<<endl;return 0;}

c++ Primer Plus（习题4.2）

//修改程序清单4.4的，用string类不是数组#include<iostream>#include<string>int main(){std::string name, dessert;std::cout << "Enter you name: \n";std::cin>>name;std::cout << "Enter your favorite dessert: \n";std::cin >> dessert;std::cout << "I have some delicious " << dessert<< "for you," << name << ".\n";return 0;}

c++ Primer Plus（习题4.3）

/*用数组拼接字符串*/#include<iostream>#include<cstring>const int Lengh=10;int main(){using namespace std;cout << "Enter your frist name: ";char fristname[Lengh];cin >> fristname;cout << "Enter your last name: ";char lastname[Lengh];cin >> lastname;char result[Lengh * 2];strcpy(result, lastname);strcat(result, ", ");strcat(result, fristname);        //这里曾异想天开的用strcpycout << "Here's the information in a single string :"<< result << endl;return 0;}

c++ Primer Plus（习题4.4）

/*用string类拼接字符串*/#include<iostream>#include<cstring>                     //可省略，利用string类的特性#include<string>int main(){using namespace std;cout << "Enter your frist name: ";string fristname;cin >> fristname;cout << "Enter your last name: ";string lastname;cin >> lastname;string result;result = lastname;//string类特性，=为字符串strcpyresult += ", ";//，+= 为加在末尾，等同于strcatresult += fristname;cout << "Here's the information in a single string :"<< result << endl;return 0;}

c++ Primer Plus（习题4.5）

/*声明一个结构的文件，主要是学会利用结构*/#include<iostream>struct CandyBar{char name[20];double weight;int calorie;};int main(){using namespace std;CandyBar snack =                 //c++中不用带struct关键字了{"Mocha Munch",2.3,350 //最后一个成员后面不用加逗号了,加了也没感觉！遗憾！};cout << "Name: " << snack.name << endl<< "Weight: " << snack.weight << endl<< "Calorie: " << snack.calorie<<endl;return 0;}

c++ Primer Plus（习题4.6）

/*声明一个结构的文件，主要是学会利用结构*//*这次要用结构数组*/#include<iostream>struct CandyBar{char name[20];double weight;int calorie;};int main(){using namespace std;CandyBar snack[3] =                 //结构数组初始化的方式，要试才知道{{"Mocha Munch",2.3,350},{ "Aca Match",4.6,750 },{ "Joa Touch",1.1,320 },};                               //没学到循环，将就着用吧cout << "#1\n";                      cout << "Name: " << snack[0].name << endl<< "Weight: " << snack[0].weight << endl<< "Calorie: " << snack[0].calorie << endl;cout << "#2\n";cout << "Name: " << snack[1].name << endl<< "Weight: " << snack[1].weight << endl<< "Calorie: " << snack[1].calorie << endl;cout << "#3\n";cout << "Name: " << snack[2].name << endl<< "Weight: " << snack[2].weight << endl<< "Calorie: " << snack[2].calorie << endl;return 0;}

c++ Primer Plus（习题4.7）

/*pizza结构，一样的味道，主要是学会利用结构*/#include<iostream>struct Pizza{char name[20];double weight;int calorie;};int main(){using namespace std;Pizza snack;               //c++中不用带struct关键字了cout << "Input company name: ";cin.get(snack.name,20);                     //这里注意不能用cin>>snack,name来获取输入行，读取单词还差不多，和c的scanf差不多，遇到空白停止读入cout << "Pizza weight: ";cin >> snack.weight;cout << "Input pizza calorie: ";cin >> snack.calorie;cout << "Hear is you input:\n";cout << "Name: " << snack.name << endl<< "Weight: " << snack.weight << endl<< "Calorie: " << snack.calorie << endl;return 0;}

c++ Primer Plus（习题4.8）

/*pizza结构，一样的味道，主要是学会利用结构*//*用new重写版*/#include<iostream>struct Pizza{char name[20];double weight;int calorie;};int main(){using namespace std;Pizza *snack=new Pizza;               //new是深蓝色色，差评，改成这种颜色了cout << "Input company name: ";cin.get(snack->name, 20);                cout << "Pizza weight: ";cin >> snack->weight;cout << "Input pizza calorie: ";cin >> snack->calorie;cout << "Hear is you input:\n";cout << "Name: " << snack->name << endl<< "Weight: " << snack->weight << endl<< "Calorie: " << snack->calorie << endl;delete(snack);return 0;}

c++ Primer Plus（习题4.9）

/*声明一个结构的文件，主要是学会利用结构*//*这次要用new来构建数组结构*/#include<iostream>struct CandyBar{char name[20];double weight;int calorie;};int main(){using namespace std;               //用new感觉无法初始化结构数组啊CandyBar *snack1 = new CandyBar;*snack1 = {"Mocha Munch",2.3,350};        //只能这样玩了，刚才犯了错误，用了snck1={"Mocha Munch",2.3,350}CandyBar *snack2 = new CandyBar;          //没理清楚指针的含义*snack2 = { "Aca Match", 4.6, 750 };CandyBar *snack3 = new CandyBar;*snack3 = {"Joa Touch",1.1,320};                             //没学到循环，将就着用吧cout << "#1\n";cout << "Name: " << snack1->name << endl<< "Weight: " << snack1->weight << endl<< "Calorie: " << snack1->calorie << endl;delete(snack1);cout << "#2\n";cout << "Name: " << snack2->name << endl<< "Weight: " << snack2->weight << endl<< "Calorie: " << snack2->calorie << endl;delete(snack2);cout << "#3\n";cout << "Name: " << snack3->name << endl<< "Weight: " << snack3->weight << endl<< "Calorie: " << snack3->calorie << endl;delete(snack3);return 0;}

c++ Primer Plus（习题4.10）

/*提示用户输入3次100米跑成绩，输出次数和平均成绩，当然用户输入也要算进去*//*分别用了vector模板类和array模板类*/#include<iostream>#include<array>#include<vector>int main(){using namespace std;double vaverage = 0,aaverage=0;array<double, 3> agrade;          //array模板类vector<double> vgrade(3);        //和数组一样的用法cout << "Input your 1st 100m grade: ";cin >> vgrade[0];vaverage += vgrade[0];                //处理平均值你懂cout << "Input your 2st 100m grade: ";cin >> vgrade[1];vaverage += vgrade[1];cout << "Input your 3st 100m grade: ";cin >> vgrade[2];vaverage += vgrade[2];vaverage/=3;cout << "Using vector stream:\n";cout << "1st grade:" << vgrade[0] << endl<< "2st grade:" << vgrade[1] << endl<< "2st grade:" << vgrade[2] << endl<< "Average grade:" << vaverage << endl;agrade[0] = vgrade[0];agrade[1] = vgrade[1];agrade[2] = vgrade[2];aaverage = vaverage;cout << "Using array stream:\n";cout << "1st grade:" << agrade[0] << endl<< "2st grade:" << agrade[1] << endl<< "2st grade:" << agrade[2] << endl<< "Average grade:" << aaverage << endl;cout << "Good Bye!";return 0;}