C语言if…else if…else语句

#include <stdio.h>

int main () {

   /* local variable definition */
   int a = 100;

   /* check the boolean condition */
   if( a == 10 ) {
      /* if condition is true then print the following */
      printf("Value of a is 10/n" );
   } else if( a == 20 ) {
      /* if else if condition is true */
      printf("Value of a is 20/n" );
   } else if( a == 30 ) {
      /* if else if condition is true  */
      printf("Value of a is 30/n" );
   } else {
      /* if none of the conditions is true */
      printf("None of the values is matching/n" );
   }

   printf("Exact value of a is: %d/n", a );

   return 0;
}