一、简介：

vector容器是一个单端容器，形式如下，

这是一个在std名字空间中定义的模板类：

namespace std
{
template <class T, class Allocator = allocator<T> >
class vector;
}

如果使用vector必须包含头文件<vector>。

二、vector类的操作：

1、创建、复制和销毁

 1 void test01(void)
 2 {
 3     vector<int> v1;
 4     cout << "v1 size: " << v1.size() << endl;
 5     showVector(v1);
 6     v1.push_back(10);
 7     v1.push_back(20);
 8     cout << "v1 size: " << v1.size() << endl;
 9     showVector(v1);
10 
11     vector<int> v2(v1);
12     showVector(v2);
13     vector<int> v3(2);
14     showVector(v3);
15     vector<int> v4(10, 2);
16     showVector(v4);
17     vector<int> v5(v4.begin(), v4.end());
18     showVector(v5);
19 
20 }

结果：

2、无修改操作：

 1 void test02()
 2 {
 3     vector<int> v1;
 4     v1.push_back(10);
 5     v1.push_back(20);
 6     v1.push_back(30);
 7     v1.push_back(40);
 8     v1.push_back(50);
 9     showVector(v1);
10     cout << "v1.size: " << v1.size() << endl;
11     cout << "v1.empty: " << v1.empty() << endl;
12     cout << "v1.max_size: " << v1.max_size() << endl;
13     cout << "v1.capacity: " << v1.capacity() << endl;
14     v1.reserve(10);
15     showVector(v1);
16     cout << "v1.size: " << v1.size() << endl;
17     cout << "v1.capacity: " << v1.capacity() << endl;
18 
19     vector<int> v2;
20     vector<int> v3;
21     v2.push_back(1);
22     v2.push_back(2);
23     v2.push_back(3);
24     v3.push_back(1);
25     v3.push_back(2);
26     v3.push_back(3);
27     v3.push_back(4);
28 
29     cout << "v2 > v3 ? ===" << (v2 > v3) << endl;
30     cout << "v2 > v3 ? ===" << (v2 < v3) << endl;
31     cout << "v2 > v3 ? ==="  << (v2 >= v3) << endl;
32     cout << "v2 > v3 ? ===" << (v2 <= v3) << endl;
33     cout << "v2 > v3 ? ===" << (v2 == v3) << endl;
34     cout << "v2 > v3 ? ==="  << (v2 != v3) << endl;
35 }

结果：

3、赋值：

 1 void test03()
 2 {
 3     vector<int> v1;
 4     vector<int> v2;
 5 
 6     v1.push_back(10);
 7     v1.push_back(20);
 8     v1.push_back(30);
 9     v2.push_back(1);
10     v2.push_back(2);
11     v2.push_back(3);
12     showVector(v1);
13     showVector(v2);
14     v1.assign(10, 44);
15     showVector(v1);
16     v2.assign(v1.begin(), v1.end());
17     showVector(v2);
18     v1.push_back(123);
19     showVector(v1);
20     v1.swap(v2);
21     showVector(v1);
22     showVector(v2);
23 
24     swap(v1, v2);
25     showVector(v1);
26     showVector(v2);
27 
28     vector<int> v3;
29     showVector(v3);
30     v3 = v2;
31     showVector(v3);
32 }

结果：

4、元素访问：

 1 void test04(void)
 2 {
 3     vector<int> v1;
 4     v1.push_back(10);
 5     v1.push_back(20);
 6     v1.push_back(30);
 7     v1.push_back(40);
 8     showVector(v1);
 9     cout << v1.at(2) << endl;
10     cout << v1[2] << endl;
11     cout << v1.front() << endl;
12     cout << v1.back() << endl;
13 }

结果：

5、迭代器操作：

 1 void test05(void)
 2 {
 3     vector<int> v1;
 4     v1.push_back(10);
 5     v1.push_back(20);
 6     v1.push_back(30);
 7     v1.push_back(40);
 8     v1.push_back(50);
 9     v1.push_back(60);
10 
11     for (vector<int>::iterator it = v1.begin(); it != v1.end(); it++)
12     {
13         cout << (*it) << " ";
14     }
15     cout << endl;
16 
17     for (vector<int>::reverse_iterator it = v1.rbegin(); it != v1.rend(); it++)
18     {
19         cout << (*it) << " ";
20     }
21     cout << endl;
22 }

结果：

 6、插入和删除元素：

 1 void test06()
 2 {
 3     vector<int> v1;
 4     v1.push_back(10);
 5     v1.push_back(20);
 6     v1.push_back(30);
 7     v1.push_back(40);
 8     showVector(v1);
 9     v1.insert(v1.begin() + 1, 23);
10     showVector(v1);
11 
12     v1.insert(v1.begin() + 2, 10, 33);
13     showVector(v1);
14     vector<int> v2;
15     v2.push_back(1);
16     v2.push_back(2);
17     v1.insert(v1.begin(), v2.begin(), v2.end());
18     showVector(v1);
19     v1.pop_back();
20     showVector(v1);
21     v1.erase(v1.begin());
22     showVector(v1);
23     v1.erase(v1.begin() + 1, v1.end() - 1);
24     showVector(v1);
25     v1.resize(5);
26     showVector(v1);
27     v1.resize(10, 45);
28     showVector(v1);
29     v1.clear();
30     showVector(v1);
31 }

结果：

 7、把vector当做普通数组使用：

 可以像使用动态数组一样使用vector。

举例：

1 void test08(void)
2 {
3     vector<char> v1;
4     v1.resize(40);
5     strcpy(&v1[0], "hello World");
6     printf("%s\n", &v1[0]);
7 }

输出hello World

8、异常处理：

 成员函数中仅at（）会抛出异常；