Increment Operator in C

#include<stdio.h>
#include<conio.h>
main()
{
int a=10;
clrscr();
printf("\n Post Increment :%d",a++);
printf("\n Pre  Increment :%d",++a);
printf("\n Post Decrement :%d",a--);
printf("\n Pre  Decrement :%d",--a);
getch();
}