vector下标操作

int main(){vector<int> ivec(10,4);for(vector<int>::size_type ix = 0; ix != ivec.size(); ix++) //用int=0没错ivec[ix] = 2;for(vector<int>::size_type ix = 0; ix != ivec.size(); ix++)cout << ivec[ix] << endl;//下标不能添加元素，下面ivec是空对象，下标只能用于获取已存在的元素vector<int> ivec0;for(vector<int>::size_type ix = 0; ix != 6; ix++) //用int=0没错//ivec[ix] = 2;错的ivec0.push_back(ix);for(vector<int>::size_type ix = 0; ix != ivec0.size(); ix++)cout << ivec0[ix] << "  " ;return 0;}