NESTED-IF- Statement:

NESTED-IF- Statement:

It's also possible to nest one if statement inside another. (For that matter, it's in general possible to nest any kind of statement or control flow construct within another.) For example, here is a little piece of code which decides roughly which quadrant of the compass you're walking into, based on an x value which is positive if you're walking east, and a y value which is positive if you're walking north:

                    if(x > 0)

                               {

                               if(y > 0)

                                              printf("Northeast.\n");

                               else         printf("Southeast.\n");

                               }

               else         {

                               if(y > 0)

                                              printf("Northwest.\n");

                               else         printf("Southwest.\n");

                               }

/* Illustates nested if else and multiple arguments to the scanf function.  */

               #include <stdio.h>

                    main()

               {

                               int    invalid_operator = 0;

                               char   operator;

                               float  number1, number2, result;

                               printf("Enter two numbers and an operator in the format\n");

                               printf(" number1 operator number2\n");

                               scanf("%f %c %f", &number1, &operator, &number2);

                               if(operator == '*')

                                              result = number1 * number2;

                               else if(operator == '/')

                                              result = number1 / number2;

                               else if(operator == '+')

                                              result = number1 + number2;

                               else if(operator == '-')

                                              result = number1 - number2;

                               else

                                              invalid _ operator = 1;

                               if( invalid _ operator != 1 )

                               printf("%f %c %f is %f\n", number1, operator, number2, result );

                               else

                                              printf("Invalid operator.\n");

               }

               Sample Program Output

               Enter two numbers and an operator in the format

               number1 operator number2

               23.2 + 12

               23.2 + 12 is 35.2