Question

Define a two-dimensional array named temp of three rows and four columns of type int such that the first row is initialized to 6,8,12,\(9 ;\) the second row is initialized to 17,5,10,\(6 ;\) and the third row is initialized to 14,13,16,20.

Short answer

Declare 'temp' as \(temp[3][4] = \\{\\{6, 8, 12, 9\\}, \\{17, 5, 10, 6\\}, \\{14, 13, 16, 20\\}\\}\).

Step-by-step solution

Understand Array Dimensions

The array 'temp' is defined as having two dimensions: it consists of three rows and four columns. This means that the array will have a structure that can be visualized as a rectangle filled with numbers, where each row has four integers.

Define the Array Type and Name

We are instructed to define a two-dimensional array of type 'int' with the name 'temp'. In programming languages like C++ or Java, you would specify the data type followed by the array's name.

Initialize the First Row

The first row of the array should be initialized with the integers \(6, 8, 12,\) and \(9\). This requires assigning these specific values to the first row of 'temp'.

Initialize the Second Row

The second row of the array is initialized with the integers \(17, 5, 10,\) and \(6\). These values are assigned to each element in the second row of the array 'temp'.

Initialize the Third Row

Finally, the third row should be initialized with the integers \(14, 13, 16,\) and \(20\), completing the initialization of the array 'temp'.

Write the Array Declaration and Initialization

In a programming language like C++, you would write this as: ```cpp int temp[3][4] = { {6, 8, 12, 9}, {17, 5, 10, 6}, {14, 13, 16, 20} }; ``` This fully declares and initializes the two-dimensional array with the specified values.

Key concepts

Array Initialization

When working with arrays in C++, initialization is a crucial step. This process involves assigning values to the elements of an array at the time of its creation. Initialization ensures that the array starts with predefined data, rather than random values that may be in memory.
Understanding how to initialize arrays properly is essential for storing and manipulating data efficiently.

In a two-dimensional array like the one in our exercise, initialization can occur with nested curly braces. For example, each row in the array is enclosed in its own set of braces. This aligns with the array's dimensions and allows values to be specified systematically.

• First row: The values are 6, 8, 12, and 9.
• Second row: The values are 17, 5, 10, and 6.
• Third row: The values are 14, 13, 16, and 20.

By initializing arrays correctly, you set your data structures up for accurate storage and avoid potential bugs in your program.

Array Declaration

Array declaration in C++ is the process where you define the array's data type, name, and its size. Declaring an array lets the compiler know how much memory should be allocated for the array based on its type and size.
For example, in C++, to declare a two-dimensional array of integers, you need to specify the number of rows and columns like so:

```cpp
int temp[3][4];
```

This line indicates that `temp` is a two-dimensional array with three rows and four columns. Each element of this array will store an integer.
Declaring arrays properly is crucial, as it sets the foundation for data retrieval and manipulation within your program. If the dimensions are incorrect, it can lead to errors when accessing array elements.

C++ Programming

C++ is a powerful, high-performance programming language that provides great flexibility for applications across various domains. It's widely used in system/software development, game development, and real-time systems. One of the key features of C++ is its ability to handle arrays efficiently.

In C++, arrays provide a way to store multiple values of the same type in contiguous memory locations. When working with arrays in C++, particularly two-dimensional arrays, there are a few important aspects to keep in mind:

• Data Types: Ensure that you know the data type of your array elements. For numerical data, commonly used types are `int`, `float`, and `double`.
• Memory Management: C++ gives you control over memory, which requires you to be careful about the size and indexing of arrays to avoid overrunning memory bounds.
• Efficiency: Arrays in C++ enable fast access and manipulation of data due to their structure. Well-written programs that utilize arrays can perform operations more quickly compared to other data structures.

By understanding array initialization and declaration, you can effectively harness the capabilities of C++ arrays to implement complex logic in your applications.