Pointer Expressions
https://www.computersprofessor.com/2016/06/pointer-expressions.html?m=0
Like other variables, pointer variables can be used in
expressions. For ex:–, if p1& p2 are properly declared & initialized pointers,
then the following statements are valid.
y=*p1 * *p2;
sum=sum + *p1;
*p2=*p2 + 10;
C allows us to add integers to or subtract integers from
pointers, as well as to subtract one pointer from another.
P1+4,
p2–2 & p1–p2 are all allowed. If p1&p2 are both pointers to the same
array, then p2–p1 gives the no of else between p1& p2.
We may also use shorthand operators with the pointers.
P1++;
sum+=*p2;
Pointers
can compared using the relational operators. The expressions such as
P1>p2, p1==p2, and p1!=p2 are allowed.
We may not use pointers in division & multiplication.
Similarly 2 pointers cannot be added.