1、push_back——将某个元素从容器后端入栈
#include <iostream>
#include <vector>
#include <string>
#include <iterator>
using namespace std;
template <class T>
class Name
{
public:
Name(T t) : name(t) {}
void print()
{
cout << name << " ";
}
private:
T name;
};
//=============================
int main ()
{
typedef Name<string> N;
typedef vector<N> V;
V v;
N n1("Robert");
N n2("Alex");
v.push_back(n1);
v.push_back(n2);
v.push_back(N("Linda"));
V::iterator It = v.begin();
while ( It != v.end() )
(It++)->print();
cout << endl;
return 0;
}
运行结果:
// Robert Alex Linda
2、rbegin、rend——容器逆序输出的头和尾
#include <iostream>
#include <iomanip>
#include <vector>
#include <string>
#include <algorithm>
#include <iterator>
using namespace std;
class ID
{
friend bool operator < ( const ID&, const ID& );
public:
ID(string name,int score) : name(name), score(score) {}
void display ()
{
cout.setf(ios::left);
cout << setw(3) << score << name << endl;
}
private:
string name; int score;
};
//-----------------------------------------------------
// 比较排序函数
bool operator < ( const ID& a, const ID& b )
{
return a.score < b.score;
}
//-----------------------------------------------------
typedef vector<ID> Vector; // 为已存在的类型重新定义一个名字
int main ()
{
Vector v;
Vector::iterator Iter;
v.push_back(ID("Smith A",96));
v.push_back(ID("Amstrong B.",91));
v.push_back(ID("Watson D.",82));
for ( Iter = v.begin(); Iter != v.end(); Iter++ )
Iter->display();
sort(v.begin(),v.end()); // 排序算法
cout << endl << "Sorted by Score" << endl;
cout << "===============" << endl;
for ( Iter = v.begin(); Iter != v.end(); Iter++ )
Iter->display();
cout << endl << "Reverse output" << endl;
cout << "===============" << endl;
Vector::reverse_iterator r = v.rbegin();
while ( r != v.rend() )
cout << r->display();
cout << endl;
return 0;
}
运行结果:
// 96 Smith A.
// 91 Amstrong B.
// 82 Watson D.
//
// Sorted by Score
// ===============
// 82 Watson D.
// 91 Amstrong B.
// 96 Smith A.
//
// Reverse output
// ===============
// 96 Smith A.
// 91 Amstrong B.
// 82 Watson D.
3、reserve——扩充容器的容量
#include <iostream>
#include <vector>
using namespace std;
int main ()
{
vector<int> v(5,0); // 5个元素并初始化为0
/*------------------------------------------------*/
cout << "Size of v = " << v.size() << endl;
cout << "Capacity v = " << v.capacity() << endl;
cout << "Value of each element is - ";
for ( int i = 0; i < v.size(); i++ )
cout << v[i] << " ";
cout << endl;
v[0] = 5; // 改变第一个元素的值
v[1] = 8;
v.push_back(3); // 为容器新建第六个元素
v.push_back(7); // 为容器新建第七个元素
cout << endl; // 容器满了以后，capacity自动增加为原来的两倍
cout << "Size of v = " << v.size() << endl;
cout << "Capacity v = " << v.capacity() << endl;
cout << "Value of each element is - ";
for ( int i = 0; i < v.size(); i++ )
cout << v[i] << " ";
cout << endl << endl;
v.reserve(100); // 将容器容量capacity增加到100
cout << "Size of v1_int = " << v.size() << endl;
cout << "Capacity v1_int = " << v.capacity() << endl;
int size = sizeof(v); //vector容器大小
cout << "sizeof v = " << size << endl;
return 0;
}
运行结果:
// Size of v = 5
// Capacity v = 5
// Value of each element is - 0 0 0 0 0
//
// Size of v = 7
// Capacity v = 10
// Value of each element is - 5 8 0 0 0 3 7
//
// Size of v = 7
// Capacity v = 100
// sizeof v = 12
4、resize——减小或者扩大容器的容量
#include <iostream>
#include <vector>
#include <algorithm>
#include <iterator>
using namespace std;
int main ()
{
vector<int> v(5);
for ( int i=0; i<5; i++ )
v[i] = i*2;
copy(v.begin(),v.end(),
ostream_iterator<int>(cout," "));
cout << endl;
v.resize(7,100);
copy(v.begin(),v.end(),
ostream_iterator<int>(cout," "));
cout << endl;
v.resize(4);
copy(v.begin(),v.end(),
ostream_iterator<int>(cout," "));
cout << endl;
return 0;
}
运行结果:
// 0 2 4 6 8
// 0 2 4 6 8 100 100
// 0 2 4 6
5、size——返回容器内元素的个数
#include <iostream>
#include <vector>
#include <algorithm>
#include <iterator>
using namespace std;
template <class T>
class Print
{
public:
void operator () (T& t)
{
cout << t << " ";
}
};
//=============================
int main ()
{
vector<char> v(5);
Print<char> print;
cout << "Size of v = " << v.size() << endl;
fill(v.begin(),v.end(),'*');
for_each(v.begin(),v.end(),print);
cout << endl;
for ( int i=0; i < v.size(); i++ )
cout << v[i] << " ";
cout << endl;
for ( int i=0; i<5; i++ )
{
cout << "Size of v = ";
for_each(v.begin(),v.end(),print);
cout << endl;
v.pop_back();
}
return 0;
}
运行结果:
// Size of v = 5
// * * * * *
// * * * * *
// Size of v = * * * * *
// Size of v = * * * *
// Size of v = * * *
// Size of v = * *
// Size of v = *
6、swap——将自身容器的内容与指定容器的内容交换
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
template <class T>
class Print
{
public:
void operator () (T& t)
{
cout << t << " ";
}
};
//=============================
int main ()
{
int ary[] = {1,2,3,4,5,6,7,8,9,10};
Print print;
vector<int> v1(ary,ary+7);
vector<int> v2(ary+7,ary+10);
cout << "Vector v1 : ";
for_each(v1.begin(),v1.end(),print);
cout << endl;
cout << "Size of v1 = " << v1.size()
<< endl << endl;
cout << "Vector v2 : ";
for_each(v2.begin(),v2.end(),print);
cout << endl;
cout << "Size of v2 = " << v2.size()
<< endl << endl;
v1.swap(v2);
cout << "After swapping:" << endl;
cout << "Vector v1 : ";
for_each(v1.begin(),v1.end(),print);
cout << endl;
cout << "Size of v1 = " << v1.size()
<< endl << endl;
cout << "Vector v2 : ";
for_each(v2.begin(),v2.end(),print);
cout << endl;
cout << "Size of v2 = " << v2.size()
<< endl << endl;
return 0;
}
运行结果:
// Vector v1 : 1 2 3 4 5 6 7
// Size of v1 = 7
//
// Vector v2 : 8 9 10
// Size of v2 = 3
//
// After swapping:
// Vector v1 : 8 9 10
// Size of v1 = 3
//
// Vector v2 : 1 2 3 4 5 6 7
// Size of v2 = 7
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