== | Returns true if the left operand is equal to the right operand. |
!= | Returns true if the left operand is not equal to the right operand. |
=== | Returns true if the left operand is identical to the right operand. This is not the same as ==. |
!== | Returns true if the left operand is not identical to the right operand. This is not the same as !=. |
< | Returns true if the left operand is smaller than the right operand. |
> | Returns true if the left operand is greater than the right operand. |
<= | Returns true if the left operand is equal to or smaller than the right operand. |
&& | Returns true if both the left operand and the right operand are true. |
|| | Returns true if either the left operand or the right operand is true. |
++ | Increments the operand by one. |
-- | Decrements the operand by one. |
+= | Increments the left operand by the right operand. |
-= | Decrements the left operand by the right operand. |
. | Concatenates the left operand and the right operand (joins them). |
% | Divides the left operand by the right operand and returns the remainder. |
| | Performs a bitwise OR operation. It returns a number with bits that are set in either the left operand or the right operand. |
& | Performs a bitwise AND operation. It returns a number with bits that are set both in the left operand and the right operand. |
There are at least 10 other operators not listed, but to be fair, you're unlikely to use them. Even some of the ones in this list are used infrequently — bitwise AND, for example. Having said that, the bitwise OR operator is used regularly because it allows you to combine values.
Here is a code example demonstrating some of the operators:
<?php
$i = 100;
$i++; // $i is now 101
$i--; // $i is now 100 again
$i += 10; // $i is 110
$i = $i / 2; // $i is 55
$j = $i; // both $j and $i are 55
$i = $j % 11; // $i is 0
?>
The last line uses modulus, which for some people takes a little bit of effort to under stand. The result of $i % 11 is 0 because $i is set to 55 and modulus works by dividing the left operand (55) by the right operand (11) and returning the remainder. 55 divides by 11 exactly five times, and so has the remainder 0.
The concatenation operator, a period, sounds scarier than it is: It just joins strings together. For
