what is ++a[b++]*a[2]+++--a[3]; and why

Question

int main ()
{
int a [6] = {1,2,3,4,5,6};
int b = 1;
int x;

++a[b++]*a[2]+++--a[3];
}

i know it will be 12, but can someone explain some details?

Answer 1

Nagendra, I think your interpretation is not entirely correct, because
++a != a[1]
Rather ++a[b++] increments the value stored at a[b], which would be ++2 = 3.
Afterwards it is multiplied by a[2]++, which is an post-incrementation of the value stored at a[2], which is 3. Since it is incremented afterwards, it remains 3, therefore 3*3 = 9.
For the last part, the value at a[3] is decremented, thus --4 = 3, and then added to 9, making the result 12.

Answer 2

See my interpretation -
++a=a[1]
b++ = Post increment. Value of b will be taken before increment.

++a[b++] =a[1 +1]= a[2] =3;
++--a[3]= a[3]=4;

++a[b++]+++--a[3] can be e interred based on operator preedance as - (++a[b++]) +(++--a[3]) = 3*4 = 12

Hope this helps...!!!