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目录
1.vector类常用接口说明
1.1默认成员函数
1.1.1构造函数(constructor)
1.1.2 赋值运算符重载(operator=())
2. vector对象的访问及遍历操作(Iterators and Element access)
3.vector类对象的容量操作(Capacity)
4. vector类对象的修改及相关操作(Modifiers and String operations)
5. 使用vector存储string对象以及实现二维数组
C++中的vector对应与C语言中的顺序表，底层还是通过数组来存储数据的。可以参考用C语言实现顺序表。vector和string不一样的是vector是类模板，类模板只能显式实例化。vector是STL中一种重要的数据结构。C++之所以设计STL就是为了统一各种数据结构的接口，所以下面介绍的vector的接口在使用上与string等其他数据结构具有相同的用法。
#include <iostream>
#include <vector>using namepsace std;int main()
{vector<int> v1; //类模板只能显示实例化return 0;
}1.vector类常用接口说明
vector类的接口我按照C++函数网址进行介绍,这里只进行常用接口的介绍,其他接口、类中的函数参数和函数重载若有需要请参考该网址,下列介绍就不一一列出了。vector的接口和string的接口很相似，可以参考C++中string类的使用进行对比。
1.1默认成员函数
1.1.1构造函数(constructor)
这里的默认构造其实和string类类似，这里就不一一说明了。
#include<iostream>
#include<vector>
#include<string>
using namespace std;void test_vector1()
{//1.defaultvector<int> v1; //size == 0 capacity == 0for (auto e : v1){cout << e << " ";}cout << endl;//2.fillvector<int> v2(10, 1); //用n个值进行初始化for (auto e : v2){cout << e << " ";}cout << endl;//3.rangevector<int> v3(++v2.begin(), --v2.end()); //用迭代器区间进行构造vector<int>::iterator it = v3.begin(); //通过迭代器进行遍历while (it != v3.end()){cout << *it << " ";it++;}cout << endl;//4.copyvector<int> v4 = v2;for (auto e : v4){cout << e << " ";}cout << endl;//5.initializer listvector<int>v5 = { 0,3,5,6,9,3,0 };for (auto e : v5){cout << e << " ";}cout << endl;
}int main()
{test_vector1();return 0;
}
1.1.2 赋值运算符重载(operator=())
#include<iostream>
#include<vector>
#include<string>
using namespace std;void test_vector2()
{vector<int> v1(10, 1);//1.copyvector<int> v2;v2 = v1;for (auto& e : v2){cout << e << " ";}cout << endl;//1.initializer listvector<int> v3;v3 = { 1,2,3,4,5,6 };for (auto& e : v3){cout << e << " ";}cout << endl;
}int main()
{ test_vector2();return 0;
}
2. vector对象的访问及遍历操作(Iterators and Element access)
vector对象的访问及遍历操作和string基本上是一模一样的，并且两个数据结构的底层都是通过数组进行实现的，参考C++中string类的使用即可。
3.vector类对象的容量操作(Capacity)
#include<iostream>
#include<vector>
#include<string>
using namespace std;void TestVectorExpand()
{//vs下是1.5倍扩容，g++下是两倍扩容size_t sz;vector<int> v;//v.reserve(99); 最少开n个sz = v.capacity();cout << "making v grow:\n";cout << "capacity changed: " << sz << "\n";for (int i = 0; i < 100; ++i){v.push_back(i);if (sz != v.capacity()){sz = v.capacity();cout << "capacity changed: " << sz << "\n";}}
}void test_vector3()
{//1.size//2.capacity//3.emptyvector<int> v1(10, 1);cout << v1.size() << endl;cout << v1.capacity() << endl;cout << v1.empty() << endl;v1.clear();cout << endl;cout << v1.size() << endl;cout << v1.capacity() << endl;cout << v1.empty() << endl;cout << "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" << endl;TestVectorExpand();//不缩容,不改变sizevector<int> v2(10, 1);v2.reserve(20);cout << v2.size() << endl;cout << v2.capacity() << endl;cout << endl;v2.reserve(15);cout << v2.size() << endl;cout << v2.capacity() << endl;cout << endl;v2.reserve(5);cout << v2.size() << endl;cout << v2.capacity() << endl;cout << endl;cout << "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" << endl;vector<int> v3(10, 1);for (auto& e : v3){cout << e << " ";}cout << v3.size() << endl;cout << v3.capacity() << endl;cout << endl;//vs不缩容，如果小于n < size，则缩到n，如果size < n < capacity,把size变为n， 如果n > capacity则扩容之后把size变为nv3.resize(15, 2);for (auto& e : v3){cout << e << " ";}cout << endl;cout << v3.size() << endl;cout << v3.capacity() << endl;cout << endl;v3.resize(25, 3);for (auto& e : v3){cout << e << " ";}cout << endl;cout << v3.size() << endl;cout << v3.capacity() << endl;cout << endl;v3.resize(5);for (auto& e : v3){cout << e << " ";}cout << endl;cout << v3.size() << endl;cout << v3.capacity() << endl;
}int main()
{test_vector3();return 0;
}
4. vector类对象的修改及相关操作(Modifiers and String operations)
#include<iostream>
#include<vector>
using namespace std;void test_vecotr4()
{vector<int> v(10, 1);v.push_back(2);v.insert(v.begin(), 5);for (auto& e : v){cout << e << " ";}cout << endl;v.insert(v.begin() + 3, 3);for (auto& e : v){cout << e << " ";}cout << endl;v.pop_back();for (auto& e : v){cout << e << " ";}cout << endl;v.erase(v.begin(), v.begin() + 3);for (auto& e : v){cout << e << " ";}cout << endl;
}int main()
{test_vector4();return 0;
}
5. 使用vector存储string对象以及实现二维数组
#include<iostream>
#include<vector>
#include<string>
using namespace std;void test_vector5()
{vector<string> v1;string s1 = "xxxxx";v1.push_back(s1);v1.push_back("yyyyy"); //隐式类型转换for (auto& e : v1) {cout << e << " ";}cout << endl;//二维数组,初始化一个10*5的二维数组vector<int> v(5, 1); //初始化行vector<vector<int>> vv(10, v); //初始化列vv[2][1] = 2;for (size_t i = 0; i < vv.size(); i++){for (size_t j = 0; j < vv[i].size(); j++){cout << vv[i][j] << " ";}cout << endl;}
}int main()
{ test_vector5();return 0;
}