std::vector的一些使用注意事项

• 使用at()函数而不是operator[]：理由是at()可以抛出invalid vector[T] subscript异常，而operator[]不会做范围检查。因此，at()函数更加安全。
• 使用vector的assign函数复制一个vector:

include "stdafx.h"

#include <vector>

#include <iostream>



int main( )

{

	using namespace std;

	vector<int> v1, v2, v3;

	vector<int>::iterator iter;



	v1.push_back(10);

	v1.push_back(20);

	v1.push_back(30);

	v1.push_back(40);

	v1.push_back(50);



	cout << "v1 = " ;

	for (iter = v1.begin(); iter != v1.end(); iter++)

		cout << *iter << " ";

	cout << endl;



	v2.assign(v1.begin(), v1.end());

	cout << "v2 = ";

	for (iter = v2.begin(); iter != v2.end(); iter++)

		cout << *iter << " ";

	cout << endl;



	v3.assign(7, 4) ;

	cout << "v3 = ";

	for (iter = v3.begin(); iter != v3.end(); iter++)

		cout << *iter << " ";

	cout << endl;

}