In the context of dashboard design, what is the significance of the 'data-ink ratio'?
- It calculates the ratio of data points to the size of the dashboard, optimizing space utilization.
- It evaluates the ratio of data points to the ink color used, emphasizing the importance of color coding.
- It measures the ratio of data points to the total number of points on a chart, ensuring data accuracy.
- It represents the ratio of data to the total ink used in a visualization, emphasizing the importance of minimizing non-data ink.
The 'data-ink ratio' represents the proportion of ink in a visualization that conveys meaningful information. It emphasizes the importance of maximizing the ink used to represent data while minimizing non-data ink, promoting clarity and efficiency in dashboard design.
In C, the function ________ is used to write formatted output to the standard output.
- display
- printf
- write
The 'printf' function in C is used for formatted output to the standard output (usually the console). It allows you to print data with specific formatting, making it a common choice for displaying results.
What is the difference between the '==' operator and the '=' operator in C?
- Assigns a value to a variable
- Checks for equality between two values
- Checks if a variable is even
- Compares two memory addresses
In C, the '==' operator is used to compare the values of two variables, while the '=' operator is used for assignment. It's a common source of bugs when they are confused.
Pointers to structures are particularly useful when you want to create ________ data structures in C.
- Complex
- Dynamic
- Simple
- Static
Pointers to structures are particularly useful when you want to create complex data structures in C. These structures can contain various data types and nested structures, enabling dynamic and complex data modeling.
What is the difference between the 'while' and 'do-while' loops in terms of their execution?
- The 'do-while' loop can only be used for iteration over arrays.
- The 'do-while' loop is not a valid loop construct in most programming languages.
- The 'while' loop always executes its code block at least once, while the 'do-while' loop may not execute it at all.
- The 'while' loop executes its code block in reverse order compared to the 'do-while' loop.
The 'while' loop and 'do-while' loop are both used for repetitive execution of a code block, but they differ in when the condition is checked. In a 'while' loop, the condition is checked before the loop body is executed. If the condition is false initially, the loop body may not execute at all. In a 'do-while' loop, the loop body is executed at least once before checking the condition. This guarantees that the code block will execute at least once, even if the condition is false.
Why is dynamic memory allocation used when dealing with arrays in C?
- To allow flexible array sizes
- To improve performance
- To reduce memory usage
- To simplify array manipulation
Dynamic memory allocation in C allows for the allocation and deallocation of memory during program execution, which is essential when the array size is not known at compile-time. It provides flexibility in memory usage.
What does the address-of operator (&) do in C?
- It is a bitwise operator.
- It multiplies the value by 2.
- It returns the address of a variable.
- It returns the value stored at the address.
The address-of operator (&) in C is used to get the memory address of a variable. This allows you to access and manipulate the variable indirectly through pointers. It does not return the value stored at the address but the address itself.
In dplyr, to perform operations on multiple columns at once, the _______ function is used.
- across()
- group_by()
- mutate()
- summarize()
The across() function in dplyr is used to perform operations on multiple columns simultaneously. It is particularly useful when you want to apply the same operation to multiple columns in a data frame.
What advanced metric is used to assess the long-term value of a customer to a business?
- Cost per Acquisition (CPA)
- Customer Lifetime Value (CLV)
- Net Promoter Score (NPS)
- Return on Investment (ROI)
Customer Lifetime Value (CLV) is a key metric in assessing the long-term value of a customer to a business. It represents the total revenue a business expects to earn from a customer throughout their entire relationship. ROI, NPS, and CPA are important metrics but focus on different aspects.
What is the primary purpose of a function in C programming?
- To declare variables
- To organize code logically
- To print text to the screen
- To run the program
In C programming, a function is primarily used to organize code logically, making it easier to manage and understand.