文件输出步骤总结:
1、建立输出流对象,并将输出流对象和输出文件名绑定:ofstream sss_out("sssout.txt");
2、向输出流输出元素,有两种方式,一种是直接输出:sss_out<<输出内容;
1 // Fig. 14.3: fig14_03.cpp
2 // Create a sequential file.
3 #include <iostream>
4 #include <string>
5 #include <fstream> // contains file stream processing types
6 #include <cstdlib> // exit function prototype
7 using namespace std;
8
9 int main()
10 {
11
12 ofstream sss_out("sssout.txt");// 建立输出流sss_out,并将输出流和文件sssout.txt绑定
13
14 // exit program if unable to create file
15 if (!sss_out) // overloaded ! operator
16 {
17 cerr << "File could not be opened" << endl;
18 exit(EXIT_FAILURE);
19 } // end if
20
21 cout << "Enter the account, name, and balance." << endl
22 << "Enter end-of-file to end input.\n? ";
23
24 int account; // the account number
25 string name; // the account owner's name
26 double balance; // the account balance
27
28 // read account, name and balance from cin, then place in file
29 while (cin >> account >> name >> balance)
30 {
31 sss_out << account << ' ' << name << ' ' << balance << endl;//向输出流输出元素
32 cout << "? ";
33 } // end while
34 } // end main
另一种可以建立输出流迭代器进行输出: ostream_iterator<int> out(out_xls," sss ");//sss为每个元素输出后输出的内容,即间隔。
1 #include<iostream>
2 #include<fstream>
3 #include<iterator>
4 using namespace std;
5
6 int main() {
7 ofstream out_xls("int.txt");
8 //istream_iterator<int> in(cin);
9 ostream_iterator<int> out(out_xls," sss ");
10 int i;
11 while (cin >> i) {
12 *out++ = i;
13 }
14
15 }