C Programming - Pointers - Discussion

Ya I know the answer is correct.

But please can anyone suggest me when we consider 16 bit compiler and when we consider 32 bit in questions. Because it is not mentioning there about 16 bit or 32 bit.

I faces this problem many times in my all test.

first of all x = 30.

x++ means x= 31.

Since the precedence of *(pointer operator) is lower than ++(post increment), *y++ means *(y++). Post increment shows its effect after execution of the very statement. So y gets incremented to 504 but its effect is ignored while executing the statement.

To better understand this take this example.

int main()
{
int i[] = {3, 5};
int *p = i;
int j = --*p++;

printf("j = %d\n\n", j);

return 0;
}

In this the statement --*p++ can be interpreted as --(*(p++)).

Here y=z; means both has same address i.e 500.

Now this expression *y++=*z++; means "whatever the the VALUE AT Z++ ,assign it to the address of y++"

Note:-here *y++ & *z++ both are post increment so...firstly expression(*y++=*z++;) is performed.

So...value at z is assigned to y(i.e nothing but 30).

And after that both address is incremented by 4 bytes(according to the question).

So finally,
x++;

Becomes 31 and z, y becomes 504, 504.

Here x = 30; y = z = 500;

Then,

*z++ = 504 = *y++;//as it takes 4 bytes.

x++ = 31;

So the answer is 31, 504, 504.

I got the answer, but after (*y++=*z++;) this expression what will the why & z point to? and what is the value at the address 504?

Please provide me full explanation.

@Vikash.

Because '=' has right to left associativity means left operand should be unambiguous but in case of y++ = z++ the '=' can't find an unambiguous operand(++ or y++).

Someone please tell.
Why compiler doesn't execute

y++ = z++;

while execute *y++ = *z++;

1. The address of x which is assumed as 500 and size is 4 byte passed to pointer y.

2. The address stored in y is passed to pointer z.

3. Then both y and z get post increment that is 500 to 504. because the size is 4 byte.

4. the value of x again incremented to 30 to 31;

ANS is = x = 31, y = 504, and z = 504.

*y++ = *z++;
Means 504 = 504;
Can anyone tell me how can I assign a value to a value?
Is this not an L-value ERROR!

Can anybody clear my doubt regarding post increment and pre increment in C? Cause here, post increment is taking place hence first value should be returned the it have to be increment. But here incremented value is returning?