Programming in C

The ifStatement 71

When writing programs, this “else” concept is so frequently required that almost all

modern programming languages provide a special construct to handle this situation. In

C,this is known as the if-elseconstruct and the general format is as follows:

if ( expression)

program statement 1

else

program statement 2

The if-elseis actually just an extension of the general format of the ifstatement. If

the result of the evaluation of expressionis TRUE,program statement 1, which

immediately follows, is executed; otherwise,program statement 2is executed. In either

case, either program statement 1or program statement 2is executed, but not both.

You can incorporate the if-elsestatement into Program 6.3, replacing the two if

statements with a single if-elsestatement.The use of this new program construct actu-

ally helps to reduce the program’s complexity and also improves its readability, as shown

in Program 6.4.

Program 6.4 Revising the Program to Determine if a Number Is Even or Odd

// Program to determine if a number is even or odd (Ver. 2)

#include <stdio.h>

int main ()

{

int number_to_test, remainder;

printf ("Enter your number to be tested: ");

scanf ("%i", &number_to_test);

remainder = number_to_test % 2;

if ( remainder == 0 )

printf ("The number is even.\n");

else

printf ("The number is odd.\n");

return 0;

}

Program 6.4 Output

Enter your number to be tested: 1234

The number is even.

TEAM FLY