Interesting Facts about C Programming

Here we will see some interesting facts about C programming. These are like below.

• Sometimes the case labels of some switch statement can be placed inside if-else statement.

Example

#include <stdio.h>
main() {
   int x = 2, y = 2;
   switch(x) {
      case 1:
         ;
         if (y==5) {
            case 2:
               printf("Hello World");
         }
         else case 3: {
            //case 3 block
         }
   }
}

Output

Hello World

• The array[index] can be written as index[array]. The reason is array elements are accessed using pointer arithmetic. The value of array[5] is *(array + 5). If this is in the reverse order like 5[array], then also this is same like *(5 + array).

Example

#include <stdio.h>
main() {
   int array[10] = {11, 22, 33, 44, 55, 66, 77, 88, 99, 110};
   printf("array[5]: %d
", array[5]);
   printf("5[array]: %d
", 5[array]);
}

Output

array[5]: 66
5[array]: 66

• We can use <: , :> in the place of square brackets [,] and <%, %> in the place of curly braces {,}.

Example

#include <stdio.h>
main() <%
int array<:10:> = <%11, 22, 33, 44, 55, 66, 77, 88, 99, 110%>;
printf("array[5]: %d
", array<:5:>);
%>

Output

array[5]: 66

• We can use #include in some strange places. Here let us consider the file abc.txt is holding the line “The Quick Brown Fox Jumps Over The Lazy Dog”. If we include the file after printf statement, we can print that file content.

Example

#include <stdio.h>
main() {
   printf
   #include "abc.txt" ;
}

Output

The Quick Brown Fox Jumps Over The Lazy Dog

• We can ignore the input using %*d in scanf().

Example

#include <stdio.h>
main() {
   int x;
   printf("Enter two numbers: ");
      scanf("%*d%d", &x);
   printf("The first one is not taken, the x is: %d", x);

}

Output

Enter two numbers: 56 69
The first one is not taken, the x is: 69