Microsoft Visual C++/cli step by Step

 

CHAPTER 5

 

Decision and loop statements 

 61

Notice that because the date you typed was invalid, the application doesn’t display it. Instead, 

it just displays “The End.” You can make the application more user-friendly by displaying an 

error message if the date is invalid. To do so, you need to use a two-way test.

performing two-way tests

The following code shows how to define a two-way test for the Calendar Assistant application:

if (month >= 1 && month <= 12 && day >= 1 && day <= 31) 

{ 

    DisplayDate(year, month, day); 

} 

else 

{ 

    Console::WriteLine("Invalid date"); 

} 

Console::WriteLine("\nThe end\n");

The else body defines what action to perform if the test condition fails.

In this exercise, you will enhance your Calendar Assistant application to display an error message if 

an invalid date is entered.

1. 

Continue working with the project from the previous exercise.

2. 

Modify the main function, replacing the simple if with an if-else statement to test for valid or 

invalid dates.

if (month >= 1 && month <= 12 && day >= 1 && day <= 31) 

{ 

    DisplayDate(year, month, day); 

} 

else 

{ 

    Console::WriteLine("Invalid date"); 

} 

Console::WriteLine("\nThe end\n");

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