C Programming - Structures, Unions, Enums - Discussion

Since Structure,Union,Enum are all User defined data types so user can use new values...thus logic is simple.. :-)

But what is the difference?

I agree with the runa and the main difference is the structure allocate different memory location with the data types but union allocate one large memory location for their members.

These are used to create a new data type that holds all data types.

Thanks for your explanation.

Question is the similarity between a structure, union and enumeration. I think These all are the user defined data type. That holds various types of other data types.

But enum will store's integer constants only. How it can store all types of datatypes.

What is union ?

Structure,union,enum all are userdefined datatypes.

Let we take one senario for structure.

Suppose in my programm i've to take the 100 variables. If you want to define many variables of different datatype, instead of declaring all those variables individually just go through sructure.Just define the one structure and take all those variables into that structure.

Then if you want to access any variable, just take the structname and dot operator and variable name.then we can access those variables.

union also used for storing the different datatypes variables. But there is small difference between structure and union.i.e
In structures we can acess all those variables at a time because of they are sharing different memory locations.

But in unions whatever we declare in the union those all are sharing same memory that's why at a time we can access only one variable. enum also used for storing user defined variable

Ex: enum { married,divorced,unmarred}

By defaultley married is indexed by o,divorced is 1, unmarried is 2.

If you want to change this order you can change by using married=10 then divorced = 11, unmarried = 12.

What is linked list in programming on C?