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.
The result of the modulus operator % has the same sign as the dividend — that is, the result of $a % $b will have the same sign as $a. For example:
<?php
echo (5 % 3)."\n"; // prints 2 echo (5 % -3)."\n"; // prints 2 echo (-5 % 3)."\n"; // prints -2 echo (-5 % -3)."\n"; // prints -2
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