stdvector - Initializing a 2D vector using initialization list in C++11 -

how can initialize 2d vector using initialization list? normal vector doing :

vector<int> myvect {1,2,3,4}; 

would suffice. 2d 1 doing :

vector<vector<int>> myvect{ {10,20,30,40},                             {50,60,70,80}                           }; 

what correct way of doing it?
, how can iterate through using for?

for(auto x: myvect) {     cout<<x[j++]<<endl; } 

this shows: 10,1 !

and way mean ?

   vector<int> myvect[5] {1,2,3,4}; 

i saw here , cant understand it! link

what correct way of doing it?

the way showed possible way. use:

vector<vector<int>> myvect = { {10,20,30,40},                                {50,60,70,80} };  vector<vector<int>> myvect{ vector<int>{10,20,30,40},                             vector<int>{50,60,70,80} }; 

the first 1 constructs std::initializer_list<std::vector<int>> elements directly initialized inner braced-initializer-lists. second 1 explicitly constructs temporary vectors moved std::initializer_list<std::vector<int>>. not make difference, since move can elided.

in way, elements of std::initializer_list<std::vector<int>> copied out myvect (you cannot move out of std::initializer_list).

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and how can iterate through using for?

you have vector of vectors, therefore need 2 loops:

for(vector<int> const& innervec : myvect) {     for(int element : innervec)     {         cout << element << ',';     }     cout << endl; } 

i refrained using auto explicitly show resulting types.

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and way mean ?

this typo. stands, it's illegal. declaration vector<int> myvect[5]; declares array of 5 vector<int>. following list-initialization therefore needs initialize array, elements of list not implicitly convertible vector<int> (there's ctor takes size_t, it's explicit).

that has been pointed out in comments of side.

i guess author wanted write std::vector<int> varray = {3, 2, 7, 5, 8};.