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. |
Assignment Operators
<?php $a = 5; ?>
<?php $a = ($b = 2) + 5; // $a = 7 ?>
<?php
$a = 2;
$a += 3; // sets $a to 5, equivalent to: $a = $a + 5;
$b = "Hello ";
$b .= "World!"; // sets $b to "Hello There!", equivalent to $b = $b . "There!"; ( dot is for contatenation)
?>
Assignment by Reference
<?php
$a = 3;
$b = &$a; // $b is a reference to $a - changes of $a will apply to $b too
echo $a . $b; // prints 33
$a = 4;
echo $a . $b; // prints 44
class C {}
$o = &new C; // as of PHP 5 classes are passed by default by reference
// as of PHP 5.3 this will throw an E_DEPRECATED error
?>
Bitwise Operators
Format |
Name |
Example |
$a & $b |
And |
1001 & 0101 = 0001 |
$a | $b |
Or (inclusive or) |
1001 | 0101 = 1101 |
$a ^ $b |
Xor (exclusive or) |
1001 ^ 0101 = 0100 |
~ $a |
Not |
~ 1001 = 0110
|
$a << $b |
Shift left |
0010 << 1 = 0100 |
$a >> $b |
Shift right |
Shift the bits of $a $b steps to the right (each step means “divide by two”) |