what is difference between array,strutter,union and pointers
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Answer / shashidhar
array can contain single data type
Structure is collection of different data types
Unions can also contain different data types, but here the
different date types share the same memory within the
computers memory
ex:
==========================
|| ||
==========================
in the above the memory between || || is shared by int,
float, double declarations in a UNION.
where as in struture || || || the memory
declared for int and float and double are different.
which implies memory utilization is better in union.
When you come to pointers, well it can point to a data type
(like int) can point to a structure (struct xyz{ };) , it
can point to a union (union item { }; ) so its like a honey
BEE it can sit on anything
| Is This Answer Correct ? | 54 Yes | 9 No |
Answer / ravi
structure is collection of different data types.
union is same as the structures, the only difference is in
memory allocation.
struct
{
int a;
float b;
};
struct s;
s.a=10;
s.b=3.0;
printf("%d%f",s.a,s.b);
For the above structure it allocates 2bytes for integer
variable and 4 bytes for flaot variable. so totally it
allocates 6bytes of memory to that structure. we can print
the s.a and s.b values as 10 and 3.0
#include<stdio.h>
union
{
int a;
char ch;
}u;
u.a=100;
u.ch='a';
printf("%d\n%d",u.a,u.ch);
But incase of union, the memory allocated is maximum
memory required among the variables. so only 4 bytes is
allocated to unions.
if u try to print the u.a, u.ch values it prints 97, 97
where the value of u.a is being assigned by u.ch . so we
cannt get value of u.a at last. It wont happen incase of
structures. so mostly we use structures in programming.
| Is This Answer Correct ? | 31 Yes | 6 No |
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