push_back的使用

 1 #include <iostream>
 2 #include <vector>
 3 #include <string>
 4 
 5 using namespace std;
 6 
 7 int main()
 8 
 9 {
10     vector<int> v1;
11     v1.push_back(10);
12     v1.push_back(11);
13     v1.push_back(12);
14 
15     vector<int> v2(v1);
16 
17     vector<int> v4(10, 8);
18     vector<int> v6(8);//输出的是8个0，
19 
20     vector<string> v5(8, "xiao cui");
21     vector<string> v7(9); //输出的是9个空串
22 
23     for (vector<int>::size_type i = 0; i != v5.size(); ++i)
24         cout << v5[i] << endl;
25 
26     cout << v1[0] << endl;
27     cout << v2[0] << endl;
28     cout << v4[0] << endl;
29     cout << v5[0] << endl;
30     cout << v6[0] << endl;
31     cout << v7[0] << endl;
32 
33     v1[0] = 100;
34     cout << v1[0] << endl;
35 
36 
37     return 0;
38 }