%*c in scanf() - what does it mean?

Question

I tried to run this program in Turbo C but couldn't decipher the output. What does this %*c mean? Any help would be appreciated.

int dd,mm,yy;
printf("
Enter day,month and year");
scanf("%d %*c %d %*c %d",&dd,&mm,&yy);  // what does %*c mean ?
printf("
The date is : %d %d %d",dd,mm,yy);

OUTPUT

Enter day, month and year 23
2
1991
3
5
The date is: 23 1991 5

Answer 1

The * in a scanf() format means 'read the data but do not assign it to a variable in the argument list'. In context, it means you could type:

18/07/2012

and get the day (18), month (7) and year (2012) interpreted correctly. The spaces in the format string are crucial and complicate things. Normally, %c reads the next character, even a space, but the spaces around the %*c conversion specifiers deal with white space, so the code needs a non-blank character to consume.

Hence the observed behaviour that when you typed:

23 2 1991 3 5

the 2 (on its own) was consumed by the first %*c and the 3 (on its own) was consumed by the second.

This is Standard C and not a peculiar feature of Turbo C (which the first edition of the question specified, but the question has been edited to remove the reference to Turbo C since I first wrote this answer).