what are the uses of % in c++

Question

eg: {
inches = (d1.inches + d2.inches) % 12;
feet = (d1.feet+d2.feet) + ((d1.inches+d2.inches) / 12);
}

Answer 1

% (modulus) gives you the remainder of the euclidian division.

For example:
42 % 5 is 2 because 42 = 5*8 + 2
x%y is 0 if x is a multiple of y
x%2 is 0 if x is even and 1 if x is odd
x%10 gives you the last digit of x
x%100 gives you the last two digits of x
etc.

Answer 2

It's the remainder of a division.
for example:
16:3= 5 remainder 1
so 16:3=5
16%3=1

it's useful, for example, with time:
170 seconds are 2 minutes and 50 seconds
infact
170:60=2 minutes
170%60=50 seconds

in your case, probably it's a matter of imperial units:
feet=inches/12
inches=inches%12

Answer 3

% is modulus or remainder operator if you write in code 40%9 it gives output 4 which is remaider. in above code it add values of inches of d1 and d2 and after dividing it with 12 gives the value of remainder as output