Question

What is the difference between one-dimensional and two-dimensional arrays in C++?

• A. One-dimensional arrays store data in a single row, while two-dimensional arrays store data in rows and columns.
• B. One-dimensional arrays can only hold integers, while two-dimensional arrays can hold any data type.
• C. One-dimensional arrays are faster to access, while two-dimensional arrays are more flexible.
• D. One-dimensional arrays are always statically allocated, while two-dimensional arrays can be dynamically allocated.

Hint:

Think of array dimensions like coordinates. A one-dimensional array needs one coordinate (an index) to find an element, like finding a house on a single street. A two-dimensional array needs two coordinates (row and column), like finding a seat in a movie theater.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Arrays in C++ are collections of elements of the same type stored in contiguous memory locations. The "dimension" of an array refers to its logical structure for accessing elements.
Step 2: Detailed Explanation:
One-dimensional arrays store data in a single row, while two-dimensional arrays store data in rows and columns: This describes the logical model of the arrays correctly. A 1D array is like a list, accessed with one index `arr[i]`. A 2D array is like a grid or table, accessed with two indices `arr[i][j]`. While all array data is ultimately stored linearly in memory, this option accurately reflects the conceptual and practical difference in their use. This statement is correct.
One-dimensional arrays can only hold integers, while two-dimensional arrays can hold any data type: This is incorrect. Both 1D and 2D arrays can be created to hold elements of any single data type (e.g., `int`, `float`, `char`, custom objects).
One-dimensional arrays are faster to access, while two-dimensional arrays are more flexible: This is misleading and generally incorrect. Element access in both types of arrays is an O(1) operation (constant time), calculated from base address and indices. The flexibility is also not inherently different.
One-dimensional arrays are always statically allocated, while two-dimensional arrays can be dynamically allocated: This is incorrect. Both 1D and 2D arrays can be allocated either statically (on the stack or in the global data segment) or dynamically (on the heap using `new`).
Step 3: Final Answer:
The most accurate and fundamental difference described in the options is the logical structure: a 1D array is a single sequence (row), while a 2D array is a table (rows and columns).