Structures And Unions

Structure Definition

Examples

 struct student { int r_no;

char name[20];

char address[20];

                        } stud1,stud2,stud3;

 struct     { int r_no;

char name[20];

char address[20];

                        } stud1,stud2,stud3;

Assigning Values

 stud1.r_no = 10;

 strcpy(stud1.name , “Ram” );

 strcpy (stud1.address , “Ayodhya”);

 scanf(“%d”,&stud2.r_no); 

 scanf(“%s”,stud2.name);

 static struct student { …} stud3 = {20, ”Bharat” ,”Ayodhya”}

 static struct student student4= {30, “Shatrughna”, “Ayodhya”}

 struct student{…} stud1 = {40, “Laxman”, “Ayodhya” } // No static!

 main()

 { struct student student2 = {…}

 }

Comparing Structures

Structures and Functions

Unions

sizeof() Operator

bitfields

Structure of Bitfields

Examples of Usage

 emp.sex = 1;

 emp.age = 50;

 scanf(“%d”,AGE); emp.age = AGE;

 sum = sum + emp.age

 if (emp.marital_status) …

 printf(“%d”,emp.age);

 Normal structure elements can be combined with bit fields

 packing will be done for cons BFs only

 struct personal

{ char name[20];

struct addr address; // structure variable

   unsigned sex :1;

  …… } emp [100];

 struct pack

 { unsigned a:2;

    int count;

    unsigned b :3; }