What does the percent sign mean in PHP?

Question

What exactly does this mean?

$number = ( 3 - 2 + 7 ) % 7;

Answer 1

% means modulus.

Modulus is the fancy name for "remainder after divide" in mathematics.

(numerator) mod (denominator) = (remainder)

In PHP

In this case, this script will echo

6 is (13 mod 7).

Where $r is for the remainder (answer), $n for the numerator and $d for the denominator. The modulus operator is commonly used in public-key cryptography due to its special characteristic as a one-way function.