**********Array****************

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*********************** ARRAYS ******************************

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1] What would the output of the following program?

main()
{
char a[] = "Visual C++";
char *b = "Visual C++";
printf("\n %d %d",sizeof(a),sizeof(b));
printf("\n %d %d",sizeof(*a),sizeof(*b));
}


2] For the following statements would arr[3] and ptr[3] fetch the same character?

char arr[] = "Surprised";
char *ptr = "surprised";


3] For the statements in 9.2 does the compiler fetch the character arr[3] and ptr[3] in the same manner?


4] What would be the output of the following program, if the array begins at address 1200?

main()
{
int arr[] = {2,3,4,1,6};
printf("%d %d",arr, sizeof(arr));
}


5] Does mentioning the array name gives the base address in all the contexts?


6] What would be the output of the following prograam, if the aray begins at address 65486 ?

main()
{
int arr[] = {12,14,15,23,45};
printf("%u %u",arr, &arr);
}


7] Are the expressions arr and &arr same for an array of 10 integers ?


8] What would be the output of the following prograam, if the aray begins at address 65486 ?

main()
{
int arr[] = {12,14,15,23,45};
printf("%u %u",arr + 1, &arr + 1);
}


9] When are 'char a[]' and 'char *a' treated as same by the compiler ?


10] Would the following program compile successfully ?

main()
{
char a[] = "Sunstroke";
char *p = "Coldwave";
a = "Coldwave";
b = "Sunstroke";
printf("\n %s %s",a,p);
}


11] What would be the output of the following program ?

main()
{
float a[] = {12.4,2.3,4.5,6.7};
printf("\n %d",sizeof(a) / sizeof(a[0]));
}


12] A pointer to a block of memory is effectively same as an array.


13] What would be the output of the following program if the array begins at 65472?

main()
{
int a[3][4] = {
1,2,3,4,
4,3,2,1,
7,8,9,0
};
printf("\n %u %u",a + 1, &a + 1);
}


14] What does the follwoing declaration mean:

int(*ptr)[10];


15] If we pass the name of a 1-D int array to a function it decays into a pointer to an int. If we pass the name of a 2-D array of integers to a function what would it decay into ?



16] How would you define the function f() in the following program?

int arr[MAXROW][MAXCOL];
fun(arr);


17] What would be the output of the following program ?

main()
{
int a[3][4] = {
1,2,3,4,
4,3,2,8,
7,8,9,0
};
int *ptr;
ptr = &a[0][0];
fun(&ptr);
}

fun(int **p)
{
printf("\n %d",**p);
}








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************************* ANSWERS ****************************

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1] 11 2
1 1


2] Yes


3] No. For arr[3] the compiler generates code to start at location arr, move past it, and fetch the character there. When it sees the expression ptr[3] it generates the code to start at location stored in ptr, add three to the pointer, and finally fetch the character pointed to.
In other words, arr[3] is three places past the start of the object named arr, whereas ptr[3] is three places past the object pointed to by ptr.


4] 1200 10


5] No. Whenever mentioning the array name gives its base address it is said that the array has decayed into a pointer. This decaying doesn't take place in two situations:

--- When array name is used with sizeof operator.
--- When the array name is an operand of the & operator.


6] 65486 65486


7] No. Even though both may give the same addresses as in (6) they mean two different things. 'arr' gives the address of the first 'int' whereas '&arr' gives the address of array of 'ints'. Since these addresses happen to be same the results of the expressions are same.


8] 65488 65496


9] When using them as formal parameters while defining a function.


10] No, because we may assign a new string ot a pointer but not to an array.


11] 4


12] True


13] 65480 65496


14] 'ptr' is a pointer to an array of 10 integers.


15] It decays into a pointer to an array and not a pointer to a pointer.


16] fun(int a[][MAXCOL])
{
}

OR

fun(int (*ptr)[MAXCOL]) /* ptr is pointer to an array */
{
}


17] 1