Data Structure

Data structure is a way of organizing all data items that can be characterized by accessing functions that are used to store and retrieve data elements. We can also say that data structure is a way of organizing all data items which not only store the element but also store the relationship also.

Data structure mainly specifies four things:

1. Organization of data.

2. Accessing methods.

3. Degree of associativity.

4. Processing alternatives for information.

Data structures are to be considered as the building blocks of the program so the choice of particular data modal depends on two considerations:

1. It must be enough rich in structure to reflect the actual relationship of the data in real world.

2. Data structure should be enough that one can easily/effectively process the data when necessary.

Data item may be a single value or it may be a set of values.

Data is a basic fact or an entity that is used in calculation and manipulation. There are two different types of data such as numerical data items and alphanumeric data items.

Integers, floating point numbers and real numbers come under numerical data items

And characters, strings come under alphanumeric data items.

The identification of the data structure is vital in nature and the structure of the input and output data can be use to derive the structure of the program. It means we can say that data structure make the effects on both structural and functional aspects of a program

We can define it as:

Algorithm + data Structure = Program

There are mainly two types of data structures:

· Primitive data structures.

· Non primitive data structures.

Primitive data structures are directly operated upon by the machine instructions while Non primitive data structures are derived from the primitive data structures.

The most commonly used operations on data structure are as follow:

· Create

· Delete

· Selection

· Updation

The create operation allocate the memory for the program elements and done with the help of declaration statement and take place during run time or compile time.

The delete operation destroys the memory space which is allocated for the specified data structure with the help of C functions like Malloc(), free().

The selection operation used for accessing a particular data item with in a specified data structure.

And the last operation; as the name implies that it updates or modified the data item with in the specified data structure.