DIFFERENCE BETWEEN ARRAY AND POINTER
ARRAY
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POINTER
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1. Array is a collection of homogeneous data elements that
are stored in successive memory locations.
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1. Pointer is a variable that holds address of another
variable.
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2. The general form of array declaration is :
Syntax :
Datatype ArrayName[size];
Example : int x[10];
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2. The general form of a pointer variable declaration is :
Syntax :
Datatype *PtrVaribale;
Example : int *ptr;
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3. The general form of initializing a array is:
Syntax :
Datatype Array[size]={List of
values};
Example: int x[4] = {2,5,1,7};
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3. The general form of initializing a pointer variable is:
Syntax :
PtrVariable = &Variable;
Example: int x, *p;
p = &x;
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4. For an array, compiler allocates memory space based on
the size of the array.
Example: int x[5];
Here, compiler allocates 10 bytes
of memory for the variable x.
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4. For any type pointer variables compiler allocates only
2 bytes of memory.
Example: int *p;
char *q;
For p compiler allocates 2 Bytes
and for q also compiler allocates 2 Bytes memory.
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5. sizeof(arrayname) gives the number of bytes of the
memory occupied by the array.
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5. sizeof(pointervaraible) returns only 2 bytes.
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6. For arrays only static memory allocation is possible.
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6. For pointer variables dynamic memory allocation is
possible.
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7. Arrays can’t be resized.
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7. Pointer allocation can be resized using realloc()
function.
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8. It cannot be reassigned.
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8. It can be reassigned.
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9. /* Example Program */
#include<stdio.h>
#include<conio.h>
main()
{
int
x[5]={2,4,6,1,3},i;
clrscr();
printf(“\nArray
Elements Are=”);
for(i=0;i<5;i++)
printf(“ %d”,x[i]);
}
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9. /* Example program for Pointer */
#include<stdio.h>
#include<conio.h>
main()
{
int x = 10,
*p=&x;
clrscr();
printf(“\nResult
= %d”,*p);
}
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