Chapter 7.9, Problem 7.23CP

Program Plan Intro

Two-dimensional array:

A two dimensional array is also called as a multi-dimensional array; a multidimensional array is that all the identical arrays are put together into a single array.

• This is useful for storing same type of multiple sets of data in same place.
• The main advantage is that one-dimensional array can hold only one set of value whereas two-dimensional array can hold multiple sets of data in the form of rows and columns.
• The structure of a multi-dimensional array is lookalike a table (that is combination of rows and columns); it contains same type of columns.
• The array elements can be referred by the index numbers of the array; the index numbers for an “n x n” size array would be from “0, 0” to “n-1, n-1”.

For example, the index numbers of “3 x 3” array would be from “0, 0” to “2, 2” (that is (0, 0), (0, 1), (0, 2), (1, 0), (1, 1), (1, 2), (2, 0), (2, 1), and (2, 2)).

Declaring two-dimensional array:

The following example illustrates the declaration of two dimensional array:

Example:

//Declaring multi-dimensional array

double testmarks[2][3];

The above statement is used to create a multidimensional array with “2” rows and “3” columns; the first subscript (that is square bracket) is used to refer the number of rows and the second subscript is used to refer the number of columns.

• The data type “double” represents that the array will hold only “double” type of data.
• The “testmarks” array can hold 6 elements (that is $\text{2 }\times \text{ 3 }=\text{ 6}$).

Initialization of two dimensional arrays:

• While initializing the values for two-dimensional array, it is need to enclose each initialization of row with set of braces.
• The extra braces which encloses the row’s initialization list are optional,
  • This extra brace helps to separate each row and the user may sometimes leave out the initializers within a row instead of omitting the initializers for the rows that follow it.
• The index numbers of “2 x 3” array would be from “0, 0” to “1, 2” .

Example:

//Initializing the multi-dimensional array

double testmarks[2][3] = {{8,5,2},{4,1,7}};

The above statement is used to create a multidimensional array with “2” rows and “3” columns and the values are assigned in testmarks[] array as,

testmarks[0][0] = 8;

testmarks[0][1] = 5;

testmarks[0][2] = 2;

testmarks[1][0] = 4;

testmarks[1][1] = 1;

testmarks[1][2] = 7;