Question Function to add commas to numbers for better readability

Salty
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13 Sep 2025 18:10 #10893 by Salty

Function to add commas to numbers for better readability was created by Salty

Greetings,

This is not my original work and the author is unknown, but I have modified it for my use case and to compile with tbaMUD v2018. The function converts an input value (currently a long int) to a string with commas. Useful especially for exp and gold values as they increase in the endgame.

Code:

char *add_commas(long long num)
{
#define DIGITS_PER_GROUP 3
#define BUFFER_COUNT 20
#define DIGITS_PER_BUFFER 32

  int i, j, len, negative = (num < 0);
  char num_string[DIGITS_PER_BUFFER];
  static char comma_string[BUFFER_COUNT][DIGITS_PER_BUFFER];
  static int which = 0;

  sprintf(num_string, "%lli", num);
  len = strlen(num_string);

  for (i = j = 0; num_string[i]; ++i)
  {
    if ((len - i) % DIGITS_PER_GROUP == 0 && i && i - negative)
      comma_string[which][j++] = ',';
    comma_string[which][j++] = num_string[i];
  }
  comma_string[which][j] = '\0';

  i = which;
  which = (which + 1) % BUFFER_COUNT;

  return comma_string[i];

#undef DIGITS_PER_GROUP
#undef BUFFER_COUNT
#undef DIGITS_PER_BUFFER
}

Converting it to an 4bit int input is trivial so I leave that to you.

You will have to change your output to characters to a string instead of an int to avoid breaking your game.

Example:

Code:

Level   1 requires:        10,000 experience,          10,000 total experience
Level   2 requires:        20,000 experience,          30,000 total experience
Level   3 requires:        30,000 experience,          60,000 total experience
Level   4 requires:        40,000 experience,         100,000 total experience
Level   5 requires:        50,000 experience,         150,000 total experience
Level   6 requires:        60,000 experience,         210,000 total experience
Level   7 requires:        70,000 experience,         280,000 total experience
Level   8 requires:        80,000 experience,         360,000 total experience
Level   9 requires:        90,000 experience,         450,000 total experience
Level  10 requires:       200,000 experience,         650,000 total experience
Level  11 requires:       220,000 experience,         870,000 total experience
Level  12 requires:       240,000 experience,       1,110,000 total experience
Level  13 requires:       260,000 experience,       1,370,000 total experience
Level  14 requires:       280,000 experience,       1,650,000 total experience
Level  15 requires:       300,000 experience,       1,950,000 total experience
Level  16 requires:       320,000 experience,       2,270,000 total experience
Level  17 requires:       340,000 experience,       2,610,000 total experience
Level  18 requires:       360,000 experience,       2,970,000 total experience
Level  19 requires:       380,000 experience,       3,350,000 total experience
Level  20 requires:       600,000 experience,       3,950,000 total experience
Level  21 requires:       630,000 experience,       4,580,000 total experience

Have fun,

Salty

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