Download Operators

Operators
Operators are symbols such as + (addition),
- (subtraction), and * (multiplication).
Operators do something with values.
$foo = 25;
$foo – 15;
// $foo and 15 are the operands,
- is the operator
Arithmetic Operators
+
*
/
%
Addition
$a + $b
Subtraction
$a - $b
Multiplication
$a * $b
Division
$a / $b
Modulus (modulus divides the first value by
the second, and returns the remainder e.g.
$foo = 9;
echo ($foo % 4);
// 1 )
Assignment Operators
Assignment operators set the value of variables
=
Assignment
$a = $b
copies $b's
value into $a
=& Reference
$a =& $b
set $a to
reference $b
Concatenation Operator
Concatenation means to put things together.
The concatenation operator puts strings together.
.
Concatenation
appends 2nd value to 1st
$first = "Barack";
$second = "Obama"
Echo ($first . " " . $second);
// Barack Obama
Comparison Operators
== Equals
=== Identical
true if $a = $b
true if $a = $b and of same type
$x = 50;
// integer
$y = "50"; // string
if ($x == $y) {
echo "$x is the same as $y";
}
// 50 is the same as 50
$x = 50;
$y = "50";
// integer
// string
if ($x === $y) {
echo "$x is the same as $y";
} else {
echo "$x is not the same as $y";
}
// 50 is not the same as 50
Comparison Operators
!= Not Equal
!== Not Identical
<
>
<=
>=
true if $a is not equal to $b
true if $a is not identical to $b
Less Than
true if $a is less than $b
Greater Than true if $a is greater than $b
Less Than or Equal to
Greater Than or Equal to
Increment/Decrement Operators
++$a
$a++
--$a
$a--
pre-increment
increments $a by 1,
then returns $a
post-increment returns $a, then
increments $a by 1
pre-decrement decrements $a by 1,
then returns $a
post-decrement returns $a, then
decrements by 1
$a = 10;
echo $a++ . "<br />";
echo $a;
// 10
11
$a = 10;
echo ++$a;
// 11
Logical Operators
AND
true if both $a AND $b are true
$a = 10;
$b = 5;
if ($a > 5 AND $b >= 5) {
echo "This is pretty cool";
}
// This is pretty cool
&& is the same as AND
Logical Operators
OR
true if either $a AND $b are true
$a = 10;
$b = 5;
if ($a > 5 OR $b > 5) {
echo "This is pretty cool";
}
// This is pretty cool
|| is the same as OR