Operators

Most PHP operators work as you think they should work:

Example	Name	Result
$a = $b	Assign	Assign value of $b to $a.
$a == $b	Equal	True if $a is equal to $b.
$a === $b	Identical	True if $a is equal to $b, and of same type.
$a != $b	Not equal	True if $a is not equal to $b.
$a !== $b	Not identical	True if $a is not equal to $b, or not of same type.
$a < $b	Less than	True if $a is strictly less than $b.
$a > $b	Greater than	True if $a is strictly greater than $b.
$a <= $b	Less than or equal to	True if $a is less than or equal to $b.
$a >= $b	Greater than or equal to	True if $a is greater than or equal to $b.
$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.
$a and $b	And	True if both $a and $b are true.
$a or $b	Or	True if either $a or $b is true.
$a xor $b	Xor	True if either $a or $b is true, but not both.
! $a	Not	True if $a is not true.
$a && $b	And	True if both $a and $b are true.
$a \|\| $b	Or	True if either $a or $b is true.

PHP supports C-style pre- and post-increment and decrement operators (e.g., "++$a;" does a pre increment) and the conditional "?:" (or ternary) operator:

(expr1) ? (expr2) : (expr3); This expression evaluates to expr2 if expr1 evaluates to TRUE, and expr3 if expr1 evaluates to FALSE.

Error Control Operators

PHP supports one error control operator: the at sign "@". When prepended to an expression in PHP, any error messages that might be generated by that expression will be ignored.
If the track_errors feature is enabled, any error message generated will be saved in the global variable $php_errormsg. This variable will be overwritten on each error, so check early if you want to use it.

Execution Operators

PHP supports one execution operator: backticks (``). Note that these are not single-quotes! PHP will attempt to execute the contents of the backticks as a shell command; the output will be returned. and can be assigned to a variable. Example: $output = `ls -al`; echo "<pre>$output</pre>"; Note: The backtick operator is disabled when safe mode is enabled.
See also system(), passthru(), exec(), popen(), and escapeshellcmd().