at函數和[]函數使用可以說是壹模壹樣. 都是為了訪問對應index中存儲的數據, 如果index大於vector的size. 兩者都是拋出out_of_range的exception.
#include?<iostream>#include?<vector>
using?namespace?std;
int?main?()
{
vector<int>?myvector(10);//?10?zero-initialized?ints //?assign?some?values: for?(size_t?i?=?0;?i?<?myvector.size();?i++)myvector.at(i)?=?i;
for?(size_t?i?=?0;?i?<?myvector.size();?i++)cout?<<?myvector.at(i)?<<?'?'?<<?myvector[i]?<<?endl;
//cout?<<?myvector.at(20);//out_of_range_exception return?0;}