PHP: Operators
By
Kristoffer Bohmann
Conscise list of operators in PHP.
Page Contents:
- String Operators
- Array Operators
- Type Operators
- Arithmetic Operators
- Assignment Operators
- Bitwise Operators
- Comparison Operators
- Control Operators
- Execution Operators
- Incrementing/Decrementing Operators
- Logical Operators
String Operators
| Operator | Example | Explanation |
| = |
$a = "Hello"; |
Set $a to "Hello". |
| .= |
$a .= " World"; |
|
| . |
$a = $a . " World"; |
Same as above. |
Array Operators
| Operator | Example | Explanation |
| + |
$a + $b |
Union of $a and $b. |
| == |
$a == $b |
TRUE if $a and $b have same key/value pairs. |
| === |
$a === $b |
TRUE if $a and $b have same key/value pairs, in the same order, and of the same types. |
| != |
$a != $b |
TRUE if $a is not equal to $b. |
| <> |
$a <> $b |
TRUE if $a is not equal to $b (same as above). |
| !== |
$a !== $b |
TRUE if $a is not identical to $b (key/value pairs differ). |
Type Operators (Object Type)
| Operator | Example | Explanation |
| instanceof |
if($a instanceof SomeClass) |
(TRUE|FALSE) |
| instanceof |
if(!($a instanceof SomeClass)) |
(TRUE|FALSE) |
Arithmetic Operators
| Operator | Example | Explanation |
| + |
$a + $b |
Addition. |
| - |
$a - $b
-$a |
Subtraction.
Same as $a * -1. |
| * |
$a * $b |
Multiplication |
| / |
$a / $b |
Division. |
| % |
$a % $b |
Modulus (negative if $b is negative). |
Assignment Operators
| Operator | Example | Explanation |
| = |
$a = "Hello"; |
Set string to a value. |
| .= |
$a .= " World"; |
Add " World" to $a. |
| . |
$a = $a . " World"; |
Concatenate strings. |
| += |
$a += 2; |
Increment. |
| -= |
$a -= 1; |
Decrement. |
Bitwise Operators
| Operator | Example | Explanation |
| & |
$a & $b |
Bits are set in both $a and $b. |
| | |
$a | $b |
Or: Bits are set in both $a and $b. |
| ^ |
$a ^ $b |
Xor: Bits are set in either $a or $b, but not both. |
| ~ |
~$a |
Not: Bits in $a are not set. |
| << |
$a << $b |
Shift the bits of $a 2 steps to the left. |
| >> |
$a >> $b |
Shift the bits of $a 2 steps to the right. |
Comparison Operators
| Operator | Example | Explanation |
| == |
$a == $b |
TRUE if $a equal to $b. |
| === |
a === $b |
TRUE if $a equal to $b and same type. |
| != |
$a != $b |
TRUE if $a not equal to $b. |
| <> |
$a <> $b |
TRUE if $a not equal to $b (same as above). |
| !== |
$a !== $b |
TRUE if $a not equal to $b, or not same type. |
| < |
$a < $b |
TRUE if integer $a smaller than integer $b. |
| > |
$a > $b |
TRUE if integer $a greater than integer $b. |
| <= |
$a <= $b |
TRUE if integer $a smaller than or equal to integer $b. |
| >= |
$a >= $b |
TRUE if integer $a larger than or equal to $b. |
Error Control Operators
| Operator | Example | Explanation |
| @ |
@file("non-existing-file.html"); |
Ignores error messages for a PHP expression - see also error_reporting(). |
Execution Operators
| Operator | Example | Explanation |
| `` |
`ls -art` |
Tries to execute a command in the backtick as a shell command. Same as shell_exec(). (Notice: `-backtick symbol is not '-single quote). |
Incrementing/Decrementing Operators
| Operator | Example | Explanation |
| ++ |
++$a |
Pre-increment. |
|
$a++ |
Post-increment. |
| -- |
--$a |
Pre-decrement. |
|
$a-- |
Post-decrement. |
Logical Operators
| Operator | Example | Explanation |
| and |
$a and $b |
TRUE if $a and $b are TRUE (&& has precedence over "and"). |
| or |
$a or $b |
TRUE if $a or $b are TRUE (|| has precedence over "or"). |
| xor |
$a xor $b |
TRUE if either $a or $b is TRUE, but not both. |
| ! |
! $a |
TRUE if $a is not TRUE. |
| && |
$a && $b |
TRUE if $a and $b are TRUE (&& has precedence over "and"). |
| || |
$a || $b |
TRUE if $a or $b are TRUE (|| has precedence over "or"). |
