Question

(Fill in the Blanks) Fill in the blanks in each of the following: a) The names of the four elements of array p (int p[4];) are ___, ___ , ___ and ___. b) Naming an array, stating its type and specifying the number of elements in the array is called __ the array. c) By convention, the first subscript in a two-dimensional array identifies an element's ___ and the second subscript identifies an element's ___. d) An m-by-n array contains __ rows, __ columns and ___ elements. c) The name of the element in row 3 and column 5 of array \(d\) is __.

Short answer

a) p[0], p[1], p[2], p[3] b) declaring c) row, column d) m rows, n columns, m*n elements e) d[2][4]

Step-by-step solution

- Identify Array Element Names

To derive the names of the elements in a one-dimensional integer array declared in C/C++ (like int p[4];), note that array indexing starts at 0. The array p with 4 elements will have indices from 0 to 3. Therefore, the names of the elements correspond to these indices prefixed by the array name 'p'.

- Define Array Declaration

Declaring an array involves specifying the array's name, its type, and the number of elements it can hold. This process sets aside memory for the array and is referred to as 'declaring' the array.

- Two-Dimensional Array Subscripts

In a two-dimensional array, by convention, the subscripts are used to access the array's elements. The first subscript usually identifies the row of the array, while the second subscript identifies the column.

- Understanding m-by-n Arrays

An m-by-n array is an array with m rows and n columns. The total number of elements is the product of the number of rows and columns.

- Accessing Elements in Two-Dimensional Arrays

When you need to access a specific element in a two-dimensional array, you use its row and column indices. In an array d, the element in row 3 and column 5 is named by using its row and column indices in the format d[row][column], considering array indexing starts at 0.

Key concepts

Array Declaration

Understanding how to declare an array in C++ is crucial for organizing and storing multiple items of the same type. An array declaration involves three important components: the name of the array, the type of elements it will store, and the number of elements it can hold. For example, int numbers[5]; declares an array named 'numbers' that can store five integer values.

An array declaration is akin to assigning a row of mailboxes to a postal worker—each mailbox will have a label and can hold a specific type of content up to a certain capacity. Similarly, each element in the array is like a 'mailbox' which can be assigned a value of the declared type.

Array Indexing

Just as every house on a street has a unique address, array indexing provides a way to individually address each element within an array. C++ arrays are zero-indexed, meaning the first element has an index of 0, not 1. This would make the elements of an array named 'data' with 3 elements as data[0], data[1], and data[2].

When you reference or modify an element, you use the array name followed by the index in square brackets. Remember, if you try to access an index that is out of range—either negative or beyond the last index of the array—you will encounter errors that could crash your program or cause unexpected behavior.

Two-Dimensional Arrays

Imagine a two-dimension array as a grid or a table, with rows and columns. In C++, a two-dimensional array is declared specifying both dimensions. An example declaration looks like int matrix[3][4]; which signifies a table with 3 rows and 4 columns.

In such an array, the first index corresponds to the row, and the second corresponds to the column. Hence, matrix[0][2] references the third element in the first row. It's as if you're playing Battleship—the row tells you which line to look at, and the column pinpoints the exact location on that line.

C++ Programming Education

When learning C++ programming, mastering arrays is like getting your tool belt before working on a construction project. Through proper C++ programming education, students gain an appreciation of arrays as a fundamental structure for handling collections of data. Good practices include understanding how to navigate with indices, initializing arrays correctly, and comprehending multidimensional arrays' layout.

Educational resources often use practical examples and exercises to solidify these concepts. By frequently applying these concepts in code, such as creating and modifying arrays, the student builds a solid foundation for tackling more advanced programming tasks and algorithms that rely heavily on array manipulation.