[Solved] I can't understand this.

Question

What is %? Example int a = 10 % 5;
Or /= (+=, - =)

Answer 1

a /= b is the same as a = a/b, same for += and -=

% is the modulus operator, it's basically the leftover of integer division:
20/6 = 3 with 2 left (20 = 3*6 + 2), so 20%6 is 2.
19%6 = 1 (19 = 3*6 + 1)
18%6 = 0 (18 = 3*6 + 0)
17%6 = 5 (17 = 2*6 + 5)
So your example 10%5 = 0

The best use for % is probably to see if a number is odd or even:
a%2 will return 0 if a is even and 1 if it's odd.

Answer 2

Thank you Robobrine!