127.字符串输入输出流

  1 #include<iostream>
  2 //用于字符串的输入输出
  3 #include<sstream>
  4 #include<cstdlib>
  5 #include<string>
  6 //用于输出到字符串
  7 #include<strstream>
  8 using namespace std;
  9 
 10 void main1()
 11 {
 12     //创建字符串流(sprintf)
 13     stringstream mystr;
 14     //输出
 15     mystr.put('X').put('Y');
 16     //相当于汇总一个字符串(sprintf)
 17     mystr << "1234" << 12.89 << 4;
 18     cout << mystr.str() << endl;
 19 
 20     //类似以下也可以调用
 21     //mystr.put  
 22     //mystr.write
 23 
 24     cin.get();
 25 }
 26 
 27 //创建结构体,从字符串中截取字符
 28 struct info
 29 {
 30     string str1;
 31     string str2;
 32     string str3;
 33     int num;
 34     char ch;
 35     double db;
 36 
 37 };
 38 
 39 void main2()
 40 {
 41     //从字符串中获取数据,相当于sscanf,把数据截取到结构体中
 42     string str1("google microsoft  apple 100  A  10.9"); 
 43     //创建结构体
 44     info inf;
 45     //建立输入流(sscanf)
 46     istringstream iput(str1);
 47     //从输入流获取数据到结构体中
 48     iput >> inf.str1 >> inf.str2 >> inf.str3 >> inf.num >> inf.ch >> inf.db;
 49     //输出结构体信息
 50     cout << inf.str1 << "
" << inf.str2 << "
" << inf.str3 << "
" << inf.num << "
" << inf.ch << "
" << inf.db;
 51 
 52     //类似以下也可以调用
 53     //iput.gcount
 54     //iput.getline();
 55 
 56 
 57     cin.get();
 58 }
 59 
 60 
 61 void main123213()
 62 {
 63     //切割数据
 64     char p[100] = "google ,microsoft , apple ,100 , A , 10.9";
 65     for (char *px = p; *px != ''; px++)
 66     {
 67         if (*px == ',')
 68         {
 69             *px = ' ';
 70         }
 71     }
 72 
 73 
 74     info inf;
 75     //建立输入流
 76     istringstream iput(p);
 77 
 78     iput >> inf.str1 >> inf.str2 >> inf.str3 >> inf.num >> inf.ch >> inf.db;//输入
 79     cout << inf.str1 << "
" << inf.str2 << "
" << inf.str3 << "
" << inf.num << "
" << inf.ch << "
" << inf.db;
 80     cin.get();
 81 }
 82 
 83 void main123123()
 84 {
 85     char str[150] = { 0 };//当作缓冲区
 86     //建立输出流,写到str中
 87     ostringstream oput(str, sizeof(str));
 88     oput << "1233a" << 12.9 << 'A';
 89     //cout << oput.str() << endl;
 90     cout << str << endl;
 91 
 92     cin.get();
 93 }
 94 
 95 //另外一种方法 用到头文件 strstream
 96 void main1232132()
 97 {
 98     char str[150] = { 0 };//当作缓冲区
 99     //创建输出流,输出到缓冲区中     ostrstream在strstream头文件中
100     ostrstream oput(str, sizeof(str));
101     oput << "1233a" << 12.9 << 'A';
102     //cout << oput.str() << endl;
103     cout << str << endl;
104 
105     cin.get();
106 }