array -same data type
structure -diff datatype

Array:Static memory allocation.
      It uses the subscript to access the array elements.

Structure:Dynamic memory allocation.
      It uses the dot(.)operator to access the structure 
members.

Array is a base pointer..
** it points to a particular memory location..

Structure is not a pointer..

chaining and open addressing in hash table ?

Array - 
* Memory (array size) is fixed
* Accessing an element in array takes constant time. E.g. -
5th element in an array can be accessed as array[4] i.e.
searching/accessing an element in array takes comparatively
less time than in structures.
* Adding/deleting an element in the array is comparatively
difficult since the data already present in the array needs
to be moved  
Structure - 
* Memory (structure size) can be changed dynamically
* Accessing an element in a list takes more time
comparatively since we need to traverse thro the list
* Adding/deleting takes less time than in arrays

collection is similar data type array
array always start from 0
array size fixed

array has indexed data type.
data type of structure is object type.

Are you sure that Structure is object oriented, because
structs came from C, and C wasn't an object-oriented
program, and C++ was using it at the beginning where now
they use class for the same function which is better

Array is a collection of a fixed number of components all of
the same type: it is a homogeneous data structure.

structs (records) - we use them to group items of different
types; a collection of a fixed number of components in which
the components are accessed by name. The components as
mention can be of different types. A struct is typically
heterogeneous.

ARRAY:- An array can't have bit fields.

STRUCTURE:- Structure can contain bit fields.

structure is user defined!


c program for printing employee details using union ??

An array behaves like a built-in data type. All we have to 
do is to declare an array variable and use it. But in the 
case of a structure, first we have to design and declare a 
data structure before the variables of that type are 
declared and used

when we are declaring an array a variable is enough with 
the size.
when we are declaring structure it contain different data 
types.

Both arrays and structures are classified as structured data
type as provide a mechanism that enables us to access and
manipulate data in relatively easy manner. but they differ
in number of ways:-
1)An array is a collection of related data elements of same
type. Structure can have elements of different types.
2. An array is derived data type whereas a structure is a
programmer defined one.
3) An array behaves like a built in data types only we need
to declare it.but in case of structures , first we have to
design and declare a data structure before the variables of
that type are declared and used.


example:of array:

#include<stdio.h>
#include<conio.h>
void main()
{
int a[5];//only declare an array variable




example of structure:
struct book_bank
{
char title[5];
char author[3];
int pages;
float price;
};// this format of defining is also known as TEMPLATE
struct book_bank book1, book2;// declaration of variable

Array is Spelled Array 

While Structure is spelled Structure.

structure: structure is a collection of variable, reference 
under convinent mean of keeping related information.

ARRAYS: -
An array may contain a number of items all of the SAME TYPE,
including user-defined types such as structures (see above).
 Structure: -
In the C programming language, a structure may contain
MULTIPLE DATA TYPES, also including arrays of those types,
and the structure becomes a USER-DEFINED type.

array starts from a

and structure means  36-24-36

most significant diffrence

array is a homogenous data types.
structure is a user defined data types...

array= array is collection of similar data items 
structure= structure is a collection of dissimilar data 
items