C Programming - Structures, Unions, Enums - Discussion

Structures: Structure is denied as a collection of similar elements with different data types. The syntax of structure is :

struct book
{
int pages;
char name;
char author;
int edition;
}b;
Unions: It is a special data type which looks like a structure but are different from each other .
The syntax of union is :
union book
{
char name;
int pages;
int edition;
};
union book b;

The major difference between is there sizes.

In structures all the sizes of attributes are considered where as in case of unions only data type with max size is considered.

Enum: These are the special variables which can assume values which have been previously defined.

Syntax is:

enum month{jan=1, feb, march, april, may}.

enum month this_month;

This_month=feb;

Structure occupies fixed width of memory space, while Union takes the required memory based on the values.

Enum has a set of value to choose from and it can be part of either the Struct/Union or stand-alone.

Explain with program enum?

Use of structure we can use multiple data types in array.
We can define structure, union and enum.

STRUCTURE:
It is a user define data type that have we use define variable of different type of data type. it have allocate individual memory to all the variables declared in the structure based on there data types

UNION:
It is same as structure but memory allocation is maximum of there data type. In union variable have share these memory.

ENUM:
It have have declared different data type. the value of data type start with 0 by default.

Ex. enum={a,b,c,d};
Here initialize the value of
a=0
b=1
c=2
d=4

But enum={a=6,b,c,d}
Here initialize the value of
a=6
b=7
c=8
d=9

How to store multiple data types in array?

Can any one give an example of enum that contains different type of data-types ?

Because these are user defined data type and each one contain own different data type collection.

An array holds a collection related data items that are all belongs to one particular data type, i.e a single name to all data items but the data items have different memory locations.

Ex. datatype array_name[size];
int array[5];
float a[10];
char a[5];

so on...

Hi, what is an array?

Please tell the proper difference between structure and enum and then union and enum?