text: I want to find out the size of ptr, i mean what is the ptr[max].
  For example if I would want to output all items of arraytest I could writeFor example if I would want to output all items of arraytest I could writeCode:#include <iostream> using namespace std; int main(void) { int arraytest[] = { 0, 1, 2, 3, 4, 5, 6 , 7, 8 ,9}; cout << "sizeof(arraytest): " << sizeof(arraytest) << endl; //working double *ptr = NULL; int input = 0; int i = 0; while (1) { cout << "Enter digit, 0 to end." << endl; cin >> input; if (input == 0) { break; } ptr = static_cast <double *> ( realloc(ptr, ((i + 1) * sizeof(*ptr))) ); ptr[i] = i; i++; cout << "sizeof(*ptr): " << sizeof(*ptr) << endl; //not working, wrong size } free(ptr); ptr = NULL; return EXIT_SUCCESS; }Which in find quite generic.Which in find quite generic.Code:for(int j = 0; j < (sizeof(arraytest) / sizeof(int)); j++) { cout << arraytest[j] << endl; }
  For the dynamic array there is no such nice way. I could only work around and count that manually (variable i).
  Is there any nice way like with sizeof?