qr code c# mvc MORE INFO in Visual C#.NET

Drawer QR Code in Visual C#.NET MORE INFO

For details about all the practice test options available, see the How to Use the Practice Tests section in this book s Introduction.

1. Correct Answers: A, C, and D A. Correct: Decimal is a value type. B. Incorrect: String is a reference type. C. Correct: System.Drawing.Point is a value type. D. Correct: Integer is a value type. 2. Correct Answer: B A. Incorrect: First, value types must be initialized before being passed to a procedure unless they are specifically declared as nullable. Second, passing a null value would not affect the behavior of a value type. B. Correct: Procedures work with a copy of variables when you pass a value type. Therefore, any modifications that were made to the copy would not affect the original value. C. Incorrect: The variable might have been redeclared, but it would not affect the value of the variable. D. Incorrect: If the variable had been a reference, the original value would have been modified. 3. Correct Answer: B A. Incorrect: The Visual Basic sample uses angle brackets rather than parentheses. The C# sample uses parentheses rather than angle brackets. B. Correct: This is the proper way to declare and assign a nullable integer. In C#, you could also use the following: int i = null; C. Incorrect: You must use the Nullable generic to declare an integer as nullable. By default, integers are not nullable. D. Incorrect: This is not the correct syntax for using the Nullable generic.

Correct Answer: D A. Incorrect: You could create a reference class; however, it could be modified when passed to a procedure. B. Incorrect: You cannot create a reference structure. C. Incorrect: You could create a value class; however, structures tend to be more efficient. D. Correct: Value structures are typically the most efficient.

1. Correct Answers: B and C A. Incorrect: Types declared as Nullable can only be value types. B. Correct: Strings are reference types. C. Correct: Exceptions are reference types. D. Incorrect: Value types derive from System.Object, so not all derived types are reference types. 2. Correct Answer: C A. Incorrect: You should order Catch clauses from most specific to most general. B. Incorrect: The first type that matches is caught and subsequent Catch clauses are skipped. C. Correct: The first type that matches is caught, and subsequent Catch clauses are skipped. Therefore, you should order Catch clauses from most specific to most general to enable you to catch errors that you have specific error-handling for, while still catching other exceptions with the more general Catch clauses. D. Incorrect: The first type that matches is caught and subsequent Catch clauses are skipped. 3. Correct Answer: A A. Correct: Using the String type to construct a dynamic string can result in a lot of temporary strings in memory because the String type is immutable. Therefore, using the StringBuilder class is preferable. B. Incorrect: Strings are limited to 32,767 bytes, not 256 bytes.

C. Incorrect: You can search and replace with a standard String class. D. Incorrect: Strings are never value types; they are reference types. 4. Correct Answer: B A. Incorrect: While this statement is true, the real advantage of using a Finally block is that code is executed even if the runtime does not throw an exception. Code in a Catch block is executed only if an exception occurs. B. Correct: Use Finally blocks for code that should run whether or not an exception occurs. C. Incorrect: The compiler will not throw an error if you do not include a Finally block. Finally blocks are optional. D. Incorrect: You can dispose of resources in a Catch block. However, the code will run only if an exception occurs. Typically, you need to dispose of resources whether or not an exception occurs.