C Programming - Structures, Unions, Enums - Discussion

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

Because these are user defined data type that use to define another data type.

Are structure & union just differ in tums of memory. Is there not any other difference.

What is linked list in programming on C?

In short structures are used to share different memory locations for variable and union is used to allocate large memory for all variables.

These are the user defined data types. But enumeration only allocate in integer data types. Then how does is allocated for new data types for others?

@Priya: In structure only collection of different type of variables which are binded in one unit but enum are they who allows us to assign a particular value from given set to variable.

ex:
enum days {MON=-1, TUE, WED, THU, FRI, SAT};

//This allows days to have val from MON,TUE, WED,THU,FRI,SAT
Whose vaule are from -1 to 4. As MON=-1,TUE=0.

Can any one explain differnce between struct and enum ?

Difference between structure and union is that......

Structure
structure allocates individual memory to all the variables declared in the structure based on there data types

whereas.....

unions allocation the memory takes place based on the variable which occupies largest memory space based on there data type

for example

if in a union 2 variables with data types char and int are given then it allocates a memory of 4 byte in GCC since it occupies more space than char the same memory is shared for both of them

The working of structure and union is the same but the difference is in their memory allocation. The size of an structure is the summation of his all the member's size while the size of a union is the same as his largest member's size.