What does this C++ statement mean?

void max_idxs(vector<int> &pidxs){
   vector<fragment *> ids;
   max_ids(ids);

   for(size_t i = 0; i < ids.size(); i++){
    int weight_idx = ids[i]->weight_idx; //Get w开发者_如何学JAVAeight index
   }
}

In this C++ code, what does it mean by int weight_idx = ids[i]->weight_idx;?

What does -> mean?

Thanks!

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x->y means (*x).y. In other words, "take the address pointed to by x, and get the variable y from the object there". Here, it means it'll get the weight_idx from the fragment pointed to by ids[i].