Lesson 4.5. PHP operators

Operator list

The PHP operators are inspired by the operators used in C. Here is a non-exhaustive list:

Arithmetic operators

Operator	Description	Comment
+	addition
-	subtraction
*	multiplication
/	division
%	modulo	Rest of the division between two integers
**	exponential

String operator

Operator	Description	Comment
.	concatenate two strings

Assignment operators

Operator	Description	Comment
=	assignment	`$a = 5;` the integer 5 is assigned to the variable `$a`
+=	addition and assignment in short form	`$a += $b` is equivalent to `$a = $a + $b;`
-=	subtraction and assignment in short form	`$a -= $b` is equivalent to `$a = $a - $b;`
*=	multiplication and assignment in short form	`$a = $b` is equivalent to `$a = $a $b;`
/=	division and assignment in short form	`$a /= $b` is equivalent to `$a = $a / $b;`
%=	modulo and assignment in short form	`$a %= $b` is equivalent to `$a = $a % $b;`
.=	concaténation and assignment in short form	`$a .= $b` is equivalent to `$a = $a . $b;`

Comparison operators

Operator	Description	Comment
==	equal to	Same values
===	equal to	Same types and values
!=	not equal to	Different values
<>	not equal to	Different type and value
!==	not equal to	Different type or value
<	less than
>	greater than
<=	less or equal to
>=	greater or equal to
<=>	an integer less, equal or greater than zero `$a <=> $b` => when `$a` is respectively less, equal, or greater than `$b`.	Since PHP 7

Bitwise operators

Operator	Description	Comment
&	bitwise AND
\|	bitwise OR
^	bitwise XOR
~	bitwise NOT
<<	bitwise left Shift
>>	bitwise right Shift

Logical operators

Unlike bitwise operators, the operators below returns only two values: TRUE or FALSE.

Operator	Description	Comment
and ou &&	logical AND
or ou \|\|	logical OR
xor	logical XOR
!	logical NOT

Example

Here is an example of some operators:

$a = '6';
$b = 4 + 2;

// True
if ($a==$b) echo "== Same values\n";
// False
if ($a===$b) echo "=== Same values and same type\n";

// False
if ($a!=$b) echo "!= Not equal\n";
// Faux
if ($a<>$b) echo "<> Different value and type\n";
// Vrai
if ($a!==$b) echo "!== Different value or type\n";

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Exercice

Let's consider the following PHP variable declarations:

<pre>
<?php
$begin = "I love this ";
$middle = "class, PHP is";
$end = " awesome!";

$string = '5';
$integer = 6;
$float = 3.2;
?>
</pre>

Concatanate and display $begin, $middle and $end.
Add $string, $integer and $float. Display the result.
Calculate 2 power 10, display the result.

Here is the expected result:

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Solution

Lesson 4.4 Summary Lesson 4.6