Which of the following is a correct way to declare a function pointer in C++?
- int func()
- int *func()
- int (*func)()
- int &func()
In C++, a function pointer points to the address of a function. The correct syntax for declaring a function pointer is type (*pointer_name) (parameter list). In the given options, int (*func)() is the correct way to declare a function pointer returning an int.
What is the significance of the "default" case in a switch-case statement?
- It handles unspecified cases
- It serves as the primary case to be executed
- It is mandatory for all switch-case structures
- Acts as the else part in if-else structures
The "default" case in a switch-case statement is executed when none of the provided "case" conditions match the switch expression's value. It serves as a fallback and handles unspecified or unexpected values, ensuring that the switch has a response for all potential input. It is similar to the "else" in if-else.
The loop do { /* code */ } while(_______); will always execute the code block at least once.
- FALSE
- 1
- TRUE
- sometimes
The "do-while" loop in C++ always executes its body once before checking the condition. So even if the condition in the "while" part is "false", the body of the loop will execute once. This differentiates it from the "while" loop which checks the condition before the first execution.
The _______ operator is used to compare whether two C++ values are not equal.
- !=
- ==
- >=
- <=
The != operator in C++ is the "not equal to" operator. It returns true if the operands on either side are not equal. For example, 5 != 3 evaluates to true, while 5 != 5 evaluates to false. The other options represent other comparison operations.
When passing by reference, changes made to the parameter within the function _______ the original argument.
- alter
- bypass
- skip
- hide
When passing arguments by reference in C++, any modifications made to the parameter within the function directly alter the original argument. This is different from passing by value, where the function works on a copy and the original remains unchanged.
How would you implement a loop that executes a specific number of times and uses an iterator?
- Use a while loop and initialize the iterator outside the loop.
- Use a range-based for loop.
- Use a for loop and compare the iterator to the container's end iterator.
- Use recursive function calls.
To execute a loop for a specific number of times using an iterator, a common approach is to use a for loop. You initialize the iterator before the loop starts, use the loop's condition to check against the container's end iterator, and increment the iterator within the loop's iteration expression.
When dealing with binary files, the ios::binary mode should be used in conjunction with another mode such as _______.
- ios::in
- ios::out
- ios::app
- ios::trunc
When working with binary files in C++, the ios::binary mode is often paired with another mode to specify the operation, such as ios::out for writing or ios::in for reading. This ensures that the file is treated as a binary file.
What is the primary difference between direct and indirect recursion?
- Direct calls itself, while indirect calls another function that calls it back.
- Direct uses less memory than indirect.
- Direct is slower than indirect.
- Direct is always safer than indirect.
Direct recursion occurs when a function calls itself directly, whereas indirect recursion involves a function calling another function that eventually calls the original function. It's a cycle of calling between two or more functions.
In a for loop, what will happen if the condition is omitted?
- It will throw a syntax error.
- The loop will execute once.
- The loop will never execute.
- The loop will execute indefinitely.
In a for loop, if the condition is omitted, it's treated as always true. Therefore, the loop will execute indefinitely unless there's a break statement or some external factor that interrupts its execution.
The conditions in a switch-case statement must be of _______ data type.
- floating
- string
- integer or enum
- boolean
In a switch-case structure in C++, the conditions or cases must be of an integer or enumeration type. Floating-point and boolean values cannot be used as cases.