11-7
#include<iostream> using namespace std; int main() { ios_base::fmtflags original_flags=cout.flags();// 保存一些参数的设置 cout<<812<<'|'; cout.setf(ios_base::left,ios_base::adjustfield);// 对齐方式变为左对齐 cout.width(10);// 输出宽度变成10 cout<<813<<815<<'\n'; cout.unsetf(ios_base::adjustfield);// 去除现在的对齐方式 cout.precision(2); cout.setf(ios_base::uppercase|ios_base::scientific);// 使用科学计数法 cout<<831.0; cout.flags(original_flags);// 恢复cout原有的设置 return 0; }
11-3
#include<fstream> using namespace std; int main() { ofstream file; file.open("test1.txt",ios_base::binary); file<<"已成功写入文件!"; file.close(); return 0; }
11-4
#include<iostream> #include<fstream> #include<sstream> using namespace std; int main() { ifstream file; file.open("list.txt"); ostringstream tmp; tmp<<file.rdbuf(); string s=tmp.str(); cout<<s; file.close(); return 0; }
list
#include<iostream> #include<fstream> #include<string> #include<stdlib.h> #include<ctime> #include<windows.h> using namespace std; struct student { int num; string ID,name,cls; }stu[83]; int main() { ifstream cinlist("list.txt"); for(int i=0;i<83;i++) { cinlist>>stu[i].num>>stu[i].ID>>stu[i].name>>stu[i].cls; } cinlist.close(); ofstream coutlist("roll.txt"); for(int j=0;j<5;j++) { int a=0; Sleep(850); srand((unsigned)time(NULL)); a=rand()%83; cout<<stu[a].num<<" "<<stu[a].ID<<" "<<stu[a].name<<" "<<stu[a].cls<<endl; coutlist<<stu[a].num<<" "<<stu[a].ID<<" "<<stu[a].name<<" "<<stu[a].cls<<endl; } coutlist.close(); return 0; }
字符数统计
#include<iostream> #include<cstring> #include<fstream> #include<sstream> using namespace std; int main() { string filename; cout<<"请输入你想要生成的文件名:"<<endl; cin>>filename; getchar(); ifstream cinfile(filename.c_str()); string sen; while(getline(cinfile,sen)) { int charnum=0,wordnum=0,linenum=0; int a=sen.size(); for(int i=0;i<a;i++) { charnum++; if(sen[i]==' '||sen[i]==','||sen[i]=='!') wordnum++; } linenum++; cout<<"行数:"<<linenum<<" "<<"列数:"<<charnum<<" "<<"单词数:"<<wordnum<<endl; } return 0; }
做不出来,找不到文件,不知道为啥书上也找不到。