Remember basic arithmetic from school? These work just
like those.
Arithmetic Operators
Example
Name
Result
-$a
Negation
Opposite of $a.
$a + $b
Addition
Sum of $a and $b.
$a - $b
Subtraction
Difference of $a and $b.
$a * $b
Multiplication
Product of $a and $b.
$a / $b
Division
Quotient of $a and $b.
$a % $b
Modulus
Remainder of $a divided by $b.
The division operator ("/") returns a float value unless the two operands
are integers (or strings that get converted to integers) and the numbers
are evenly divisible, in which case an integer value will be returned.
Operands of modulus are converted to integers (by stripping the decimal
part) before processing.
Note:
Remainder $a % $b is negative for negative
$a.