In a graphics program, you need to define colors where each color can be represented as either a name or an RGB triplet. How would you efficiently represent this in C?
- Using a function
- Using a structure
- Using a union
- Using an enum
In C, a union would efficiently represent colors that can be either a name or an RGB triplet because it allows sharing the same memory location for different data types. Enums, structures, and functions are not suitable for this purpose.
How does the execution stack change when a recursive function is called in C?
- A new thread is created
- Each function call adds a new stack frame
- The stack remains unchanged
- The stack shrinks
In C, when a recursive function is called, each function call adds a new stack frame to the execution stack. These stack frames store the local variables and return addresses for each function call. This process continues until the base case is reached.
The ________ directive is used to define symbolic names or constants in a C program.
- #constant
- #define
- #enum
- #import
The correct answer is (b) #define. In C, the #define preprocessor directive is used to define symbolic names or constants. These names can simplify your code and make it more readable.
What would be the result of trying to access an array with a pointer that has not been initialized?
- It will access a random memory location, leading to undefined behavior.
- The pointer will point to the beginning of the array.
- The program will compile but throw a runtime error.
- The program will not compile.
Accessing an array with an uninitialized pointer in C leads to undefined behavior because the pointer doesn't point to a valid memory location. The result is unpredictable and can lead to crashes or incorrect data manipulation.
When declaring a string literal in C, which character is automatically appended at the end?
- Exclamation mark '!'
- Null terminator ' '
- Question mark '?'
- Semicolon ';'
In C, a null terminator ' ' is automatically appended at the end of a string literal. This null character indicates the end of the string, allowing C functions to determine the string's length.
When passing an array to a function in C, what is actually being passed?
- A pointer to the first element
- The entire array
- The size of the array
- The value of the first element in the array
In C, when passing an array to a function, only a pointer to the first element is passed, allowing the function to access the entire array.
When opening a file with fopen, what happens if the file does not exist and the mode is set to 'r'?
- It appends data to the existing file.
- It creates a new file.
- It overwrites the file's content.
- It returns a NULL pointer.
When opening a file with fopen in read mode ('r') and the file doesn't exist, it returns a NULL pointer, indicating that the file was not successfully opened.
An enumeration is a user-defined data type that consists of integral ________.
- Characters
- Functions
- Pointers
- Values
An enumeration is a user-defined data type that consists of integral values, typically used for defining a set of named integer constants.
The ________ algorithm is known for its simplicity but is inefficient for sorting large datasets.
- Bubble Sort
- Merge Sort
- Quick Sort
- Selection Sort
The correct option is 'Bubble Sort'. While Bubble Sort is easy to understand, it is not efficient for large datasets due to its O(n^2) time complexity.
A two-dimensional array can be visualized as a ________.
- Linked List
- One-dimensional array
- Table
- Tree Structure
A two-dimensional array can be visualized as a table with rows and columns.
When defining a bit field, what does the number after the colon represent?
- Bit order
- Bit position
- Bit size
- Bit value
The number after the colon represents the bit size, indicating how many bits the bit field can occupy.
What is the main difference between function declaration and function definition in C?
- Declarations contain the function's code
- Declarations specify the function's name
- Definitions declare the function's return type
- Definitions provide the function's implementation
The main difference between function declaration and function definition in C is that declarations specify the function's name and data types, while definitions provide the actual implementation of the function.