How in C ++ to create a constant array of numbers with symbolic indices, for example, from 'a' to 'f'? Desirable simpler. :) That is, in Delphi it would be so

a : array['a'..'f'] of longint = (1, 2, 3, 4, 5, 6);

    5 answers 5

    I will add the answer given by @ cy6erGn0m

     enum { RESULT_ERROR; } int start; int end; int* makeArray( char first, char second) { start = (int)first; end = (int)second; return new int[second-first+1]; } int get( int *array, char ch){ int index = (int)ch; if (first > index || index > end) return RESULT_ERROR; return array[index-first]; }
    • That's just the RESULT_ERROR can match the value of something lying in the array. I think this is too dangerous. One must either fall completely or throw a C ++ exception. - cy6erGn0m

    If your example is right, then no array is needed. Just instead of a [idx] is necessary (idx - 'a')

    If you really need to associate characters with numbers, then there will be something like this:

     const int a[] = {1, 2, 3}; const char a_max_idx = 'a' + sizeof(a) / sizeof(int); int get(char idx) { if (idx < 'a' || idx >= a_max_idx) die("....."); return a[idx - 'a']; }

      You can use std :: map. For example, something in the spirit of this . The advantage is the compactness of the code and its storage in the memory in case some non-continuous subset of ASCII or Unicode is required. At the same time easy to alter the lines.

         #include <iostream> using namespace std; enum abc {a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, v, w, x, y, z}; int name[j]; int main(){ name[f]=2; cout << name[f] << endl; return 0; }

        If I understand you correctly. This option works, but it is not convenient, it will be easier for you to use the usual name index [3], and the program will work faster.

          Agree with comrade gecube. For this, std: map is best suited. Of course, to initialize it also compactly and elegantly fail.

          For the future, for questions on containers I recommend: http://www.cplusplus.com/reference/stl/

          • The hash table is more general, but it requires more resources. In this case, it is better not to use the map. - cy6erGn0m
          • Hmm, why not use it? - XeoN pm
          • 2
            Because "what for". Indexing is calculated directly without any hash functions. - alexlz 1:28 pm
          • Because mapa is much more expensive and slower than simple indexing - cy6erGn0m