How does Bash modulus/remainder work?

Question

Can somebody explain how it works? I just don't understand it. Why we get 2 from

expr 5 % 3

or 1 from

expr 5 % 4

Answer 1

x % y gives you the remainder of x/y.

For example, 3 goes into 5 one time. if you subtract 3 from 5, it gives 2. This is what is left over.

In 7 % 3, 3 goes into 7 twice (3*2 < 7, 3*3 > 7). If you subtract 3*2, or 6 from 7, you get one.

7 % 3 == 1

Answer 2

Modulo/modulus is the remainder of the integer division operation. In your first example:

5 % 3

This evaluates to 2 because dividing 5 by 3 leaves 2 remaining.

Answer 3

The modulo operation finds the remainder after division of one number by another.

5 / 3 = 1 remainder 2

5 / 4 = 1 remainder 1