Program only accept number in c

I was given this question.

Input program only with numbers 0-9. The first input must include the code {1,0,3,7,0,3,1,1}. Input must be equal to 15 digits. If it is wrong it will ask for user input again.

I have a problem in accepting only the numbers 0-9. When I input a wrong command like 10370311abcdefg, it will asks the user to input again. But if I input a correct one like 10370311456789, it also will ask the user to input again which should be stopped. The printf for the correct answer does not come out.

Here this code:

int main() {        char nim[16];      char kode[8] = {'1', '0', '3', '7', '0', '3', '1', '1'};      do {          printf("NIM = ");          gets(nim);          int panjang = strlen(nim);          int benar = 0;          bool cekang =false;          for (int i = 0; i < 8; i++) {              if(nim[i] != kode[i]){                  benar = 1;                break;              }          }                    if (panjang < 15) {              printf("Kurang dari 15!\n");          }else if(panjang > 15){              printf("Lebih dari 15\n");          }else if(panjang == 15 && benar == 1){              printf("All Required Characters not present\n");          }else if(panjang == 15 && benar == 0){               for(int i = 0;i < panjang;i++){                  if(!(nim[i] >= '0' && nim[i] <= '9')){                   printf("hanya0-9\n");                   cekang=false;break;                  }              }                            if(cekang==true){                  printf("sucsess!\n");break;              }                        }      } while (true);  }  

https://stackoverflow.com/questions/66512714/program-only-accept-number-in-c March 07, 2021 at 10:40AM