int-read-1.c - En mere brugbar udgave med mulighed for fortegn og bedre linieafslutning.

Lektion 4 - slide 10 : 13 Program 2

#include <stdio.h>

int read_int(char*);

int main(void) {
  int i, n = 0;

  for (i = 1; i <= 5; i++){
    n = read_int("Enter an integer: ");
    printf("Decimal value: %d\n", n);
  }

  return 0;
}

int read_int(char *prompt){
  int res = 0;  char c; int sign = 1;
  printf(prompt);

  /* Handle initial sign, if any */
  c = getchar();
  if (c == '+') {sign = 1; c = getchar();}
  else if (c == '-') {sign = -1; c = getchar();}

  /* Read digits - first char is ready in c*/
  while (isdigit(c)){
    res = res * 10 + (c - '0');
    c = getchar();
  }

  /* read rest of line */
  while (c != '\n') c = getchar();

  return sign * res;
}