C Programming - Pointers - Discussion

It is already given that size is 4.

As it depends on 16byte or 32byte?

First x = 30.

x++ means x= 31.

*y++ means *(y++) =*(z++) it means y = z = 504.

Means only pointer of address variable i.e y and z increase not value.

X=30;
X++=31;
Y=&X;
&X=500;
Y=500;

Z=Y=500; SO *Y++=500+4=504 because pointer size is 4 bytes given.

*z++=*y++; *z++,*y++ is same.

So x=31;z=504;y=504.

x = 30.
x++ = 31.
And z++ = 500+sizeof(int) = 504.
Same as y = 504.

Here x = 30; y = z = 500;
Then,

*z++ = 504 = *y++;//inc takes 4 bytes.
x++ = 31;

So the answer is 31, 504, 504.

@Samiksha.

You wrote that
" The value of x increases by 1, which is normal variable
But the values of *y and *z are seen to decrease by 4 (bytes)
This happens because the memory addresses are arranges in descending order from top to bottom, so when 500 becomes 496, it actually means that the pointer values has INCREASED! "

But I think you are doing mistake in -ve and +ve addresses.
You may got o/p like this:

x=30, y=-4352852, z=-4352852.
x=31, y=-4352848, z=-4352848.

Please check this,

y=-4352852, z=-4352852.
y=-4352848, z=-4352848.

Value of y is negative.
-4352852 + 4 = -4352848.

If value of y is +ve, then o/p will be like:
y=+4352852, z=+4352852.
y=+4352856, z=+4352856.

y* and z* are integer data types.so when ++y* and ++*z represents,
++*y=y+4bytes and ++*z=z+4 because * is address of corresponding variable but not its value as integer normally takes 2 bytes but according to comments it is represented as 4 bytes.

y=&x; //address of x i.e 500 is assigned to y.

z=y; // pointer y contains address value of x i.e 500 is assigned to z.

*y++=*z++; //first value with in z pointer assigned to y, then z is incremented to next memory location i.e 504. Now y is incremented to next memory location i.e 504.

x++; // value contained by x i.e 30 incremented to next number 31.

printf("x=%d, y=%d, z=%d\n", x, y, z); // values are printed.

Since ++ and * have the same precedence and it'll be evaluated from right to left so the answer will be 500 and integer 4 bytes will added to 500 so it will be 504

*y++ = *z++;.

We had assume address of y as 500 and added integer 4 bytes to it.

And evaluated the expression from right to left.

Therefore answer will be 504 for y and z. And x is incremented to 31.

This is all about precedence, suffix ++ has higher precedence than * and prefix ++. So, *y++ equal to *(y++). Since ++ is suffix, So first *y and then y++.