Page 53 - DCAP201_FUNDAMENTALS_OF_DATA_STRUCTURES

Fundamentals of Data Structures

Notes The general form for declaring a single dimensional array is:
data_type array_name[expression];
where data_type represents data type of the array. That is, integer, char, float etc. array_name is
the name of array and expression which indicates the number of elements in the array.

Example: consider the following C declaration:
int a[100];
It declares an array of 100 integers.

The amount of storage required to hold an array is directly related to its type and size. For a
single dimension array, the total size in bytes required for the array is computed as shown
below.

Memory required (in bytes) = size of (data type) X length of array
The first array index value is referred to as its lower bound and in C it is always 0 and the
maximum index value is called its upper bound.

Did u know? The number of elements in the array, called its range is given by upper
bound-lower bound.
We store values in the arrays during program execution. Let us now see the process of initializing
an array while declaring it.
int a[4] = {34,60,93,2};
int b[] = {2,3,4,5};
float c[] = {-4,6,81,” 60};
We conclude the following facts from these examples:

If the array is initialized at the time of declaration, then the dimension of the array is
optional.

Till the array elements are not given any specific values, they contain garbage values.

Example: Let us consider the following figure 4.1.
(a) Array DATA be a 6-element linear array of integers such that
DATA[1]=247, DATA[2]=56, DATA[3]=429, DATA[4]=135, DATA[5]=87,
DATA[6]=156.
The following figures 4.1 depict the array DATA.
Figure 4.1: Array DATA

(a) (b)

Source: http://www.csbdu.in/econtent/DataStructures/Unit1-DS.pdf

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