The operator used to determine the remainder when one number is divided by another is _______.
- *
- %
- /
- +
In C++, the modulo operator % is used to determine the remainder of a division operation between two numbers. For example, 7 % 3 would yield a result of 1, as when 7 is divided by 3, the remainder is 1. It's a very useful operator, especially in situations that require calculations around loops and array indices.
When replacing nested if-else structures with a switch-case, what is a common pitfall to avoid?
- Ignoring the break statement
- Using non-integer values for cases
- Avoiding the default case
- Putting the default case at the beginning
When using switch-case statements, it's essential to remember to include the "break" statement at the end of each case. Without it, the program may execute subsequent cases, leading to unintended behavior known as "fall-through." The "break" statement ensures that once a match is found, no other cases are executed.
Your team is developing a C++ application involving several classes with complex interrelationships and data handling. How can abstraction be effectively implemented to simplify the interactions between different class objects and the user?
- Use multiple inheritance for all classes.
- Avoid using classes and focus on procedural programming.
- Use a single class for all functions and data.
- Define clear interfaces for classes and hide complex implementations behind those interfaces.
Abstraction involves isolating the complex reality while exposing only the necessary parts. In the context of object-oriented programming, this means defining clear interfaces for classes, which allows interactions based on these interfaces, hiding the internal complex workings. This makes the software design more understandable and manageable.
To prevent memory leaks, every call to new should be matched with a call to _______.
- delete
- free
- clear
- remove
When dynamic memory allocation is done using new, it's necessary to release that memory using delete to prevent memory leaks in C++. This ensures that every byte of memory allocated is properly released, maintaining the health and efficiency of the system.
Which of the following data types is not a primitive data type in C++?
- int
- float
- string
- double
While "int", "float", and "double" are primitive data types in C++, the "string" data type is a part of the C++ Standard Library and is, in fact, a class, not a primitive data type.
How does encapsulation aid in reducing software development complexity?
- By allowing multiple inheritance.
- By segregating the program into separate modules.
- By promoting reusability of code.
- By bundling data and methods that operate on that data.
Encapsulation in C++ is the bundling together of data and the methods that operate on that data, restricting direct access to some of the object's components. This is a fundamental concept in object-oriented programming. By encapsulating data and functions into a single unit, we can hide the internal details and reduce complexity.
To achieve runtime polymorphism in C++, _______ are used.
- classes
- macros
- virtual functions
- inline functions
Runtime polymorphism in C++ is achieved through the use of virtual functions. These are functions in the base class that you can override in derived classes. The decision about which method to call (the one in the base class or the one in the derived class) is made at runtime, based on the actual type of the object being pointed to, rather than the type of the pointer. This allows for more dynamic behavior and is a core feature of object-oriented programming in C++.
What is the default access specifier for a base class in C++?
- private
- public
- protected
- internal
In C++, if you don't specify an access specifier for the members of a class, they are implicitly set to private. This means that they can't be accessed or viewed from objects of the class or any derived class unless friends.
How does C++ handle char literals that are assigned to unsigned char variables?
- Converts to signed char
- Preserves exact value
- Converts to int
- Triggers an error
When a char literal is assigned to an unsigned char variable, C++ preserves its exact value. If the char literal's value is negative, when assigned to an unsigned char, it wraps around using standard two's complement arithmetic.
Which of the following smart pointers does not take ownership of the pointed object?
- unique_ptr
- shared_ptr
- weak_ptr
- auto_ptr
weak_ptr is a smart pointer that holds a non-owning reference to an object managed by shared_ptr. It doesn't affect the reference count and won't prevent the object from being deleted.