Answer Posted / fazlur rahaman naik

With the help of pointer we can access a variable
address.with that we can change the value of the
variable.for eg:

main()
{
int a = 10;
int *x;

x = &a;

printf("a = %d\n",a);
*x = 978;
printf("a = %d\n");
}

now the value of the a is 978.

if we pass a pointer to a variable to a function then the
value of that variable will be chageed if we change it in
that function.
for eg:

main()
{
int b = 87;
int *x;
x = &b;
fun(x);
printf("b = %d\n");
}

fun(int *x)
{
*x = 879;
}

here the value of the b will be 879.

Array : Array is a collection of variable of similar types.
i.e. it can b an collection of n number of integers or arry
of characters etc.
for eg:

Take a examination marks of a class.it could b a float
value or a integer value.Then u need to take five variables
of float type or interger type.Insted of that u can take an
array of float or integer type.

float marks[n];

arrays r mainly used for strings.

char string[n];

Structure:
The structure is a collection of variables of various data
types.

the best example for this is employee details or student
details.

struct emloyee
{
char name[25];
int age;
float salary;
char mobile[15];
char desig[25];
};

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