Short Notes: Structure & Union | Short Notes for Computer Science Engineering - Computer Science Engineering (CSE) PDF Download

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STRUCTURE AND UNION
Definition
A Structure is a user defined data type that can store related information together. The variable 
within a structure are of different data types and each has a name that is used to select it from the 
structure. C arrays allow you to define type of variables that can hold several data items of the 
same kind but structure is another user defined data type available in C programming, which 
allows you to combine data items of different kinds.
Structures are used to represent a record, Suppose you want to keep track of your books in a 
library. You might want to track the following attributes about each book:
• Title
• Author
• Subject
• Book ID
Structure Declaration
It is declared using a keyword struct followed by the name of the structure. The variables of the 
structure are declared within the structure.
Example:
Struct struct-name
{
data type var-name; 
data type var-name;
};
Page 2


STRUCTURE AND UNION
Definition
A Structure is a user defined data type that can store related information together. The variable 
within a structure are of different data types and each has a name that is used to select it from the 
structure. C arrays allow you to define type of variables that can hold several data items of the 
same kind but structure is another user defined data type available in C programming, which 
allows you to combine data items of different kinds.
Structures are used to represent a record, Suppose you want to keep track of your books in a 
library. You might want to track the following attributes about each book:
• Title
• Author
• Subject
• Book ID
Structure Declaration
It is declared using a keyword struct followed by the name of the structure. The variables of the 
structure are declared within the structure.
Example:
Struct struct-name
{
data type var-name; 
data type var-name;
};
Structure Initialization
Assigning constants to the members of the structure is called initializing of structure.
Syntax:
struct structname 
{
data type membernamel;
data type member_name2;
} struct_var={constant1,constant2};
Accessing the Members of a structure
A structure member variable is generally accessed using a ‘.’ operator.
Syntax: strcut_var. 
membername;
The dot operator is used to select a particular member of the structure. To assign value to the 
individual
Data members of the structure variable stud, we write,
stud.roll=01;
stud.name= ” Rahul” ;
To input values for data members of the structure variable stud, can be written as,
scanf(“%d” , &stud.roll); 
scanf(‘ ’ %s” , &stud.name);
To print the values of structure variable stud, can be written as: 
printf(“%s” ,stud. roll); 
printf(“%f” ,stud. name);