C语言逻辑运算符

#include <stdio.h>

main() {

   int a = 5;
   int b = 20;
   int c ;

   if ( a && b ) {
      printf("line 1 - Condition is true\n" );
   }

   if ( a || b ) {
      printf("line 2 - Condition is true\n" );
   }

   /* lets change the value of  a and b */
   a = 0;
   b = 10;

   if ( a && b ) {
      printf("line 3 - Condition is true\n" );
   } else {
      printf("line 3 - Condition is not true\n" );
   }

   if ( !(a && b) ) {
      printf("line 4 - Condition is true\n" );
   }

}