Arrays

In C language, arrays are reffered to as structured data types. An array is defined as finite ordered collection of homogenous data, stored in contiguous memory locations.
Here the words,

• finite means data range must be defined.
• ordered means data must be stored in continuous memory addresses.
• homogenous means data must be of similar data type.

Example where arrays are used,

• to store list of Employee or Student names,
• to store marks of a students,
• or to store list of numbers or characters etc.

Since arrays provide an easy way to represent data, it is classified amongst the data structures in C. Other data structures in c are structure, lists, queues and trees. Array can be used to represent not only simple list of data but also table of data in two or three dimensions.

Declaring an Array

Like any other variable, arrays must be declared before they are used. General form of array declaration is,

data-type variable-name[size];

for example :
int arr[10];

Here int is the data type, arr is the name of the array and 10 is the size of array. It means array arr can only contain 10 elements of int type. Index of an array starts from 0 to size-1 i.e first element of arr array will be stored at arr[0] address and last element will occupy arr[9].