Structures in C

Primitive types:

• Using primitive variables, we can store only 1 value at a time.
• To store more than one value, number of variables need to be declared.
• It is complex to work with number of variables in the program.
• For example,
  • Int A;
  • A=10;
  • A=20;
  • Print(A);

Derived types:

• Array is a derived data type.
• We can store more than one element into a single variable.
• For example,
  • Int arr[5] = {10, 20, 30, 40, 50};
• Drawback: We can store only homogenous data elements, hence we cannot store records.

User defined types:

• Structures and Unions are called User defined data types.
• We can store more than one element of different types.
• We can store records information
  • Employee details
  • Student details
  • Account details.

Creating the structure: “struct” is a keyword and is used to define Structure or Union.

• Structure gets memory when we declare variable for that structure.
• Structure block size is equals to sum of each element size defined in that structure.
• Just like array, structure variable holds the base address of memory block.

• We can initialize the structure directly using assignment operator.
• How we assign values to array, in the same way we can assign values to structure.
• While assigning, we need to follow the order of structure elements.

#include<stdio.h>
struct Emp
{
	int no;
	char name[20];	
	float salary;
};
int main()
{
	struct Emp x = {101, "amar", 50000};	
	printf("No : %d \n", x.no);
	printf("Name : %s \n", x.name);
	printf("Salary : %f \n", x.salary);
	return 0;	
}