PHP 5 Operators

Related Articles

How to get the common sub string in two string?

April 14, 2014

PHP 5 Global Variables – Superglobals

October 11, 2013

PHP 5 Sorting Arrays

October 11, 2013

This chapter shows the different operators that can be used in PHP scripts.

PHP Arithmetic Operators
Operator Name Example Result
+ Addition $x + $y Sum of $x and $y
– Subtraction $x – $y Difference of $x and $y
* Multiplication $x * $y Product of $x and $y
/ Division $x / $y Quotient of $x and $y
% Modulus $x % $y Remainder of $x divided by $y
** Exponentiation $x ** $y Result of raising $x to the $y’th power (Introduced in PHP 5.6)
The example below shows the different results of using the different arithmetic operators:

Example

	<?php
	$x=10;
	$y=6;
	echo ($x + $y); // outputs 16
	echo ($x - $y); // outputs 4
	echo ($x * $y); // outputs 60
	echo ($x / $y); // outputs 1.6666666666667
	echo ($x % $y); // outputs 4
	?>

PHP Assignment Operators
The PHP assignment operators are used to write a value to a variable.

The basic assignment operator in PHP is “=”. It means that the left operand gets set to the value of the assignment expression on the right.

Assignment Same as… Description
x = y x = y The left operand gets set to the value of the expression on the right
x += y x = x + y Addition
x -= y x = x – y Subtraction
x *= y x = x * y Multiplication
x /= y x = x / y Division
x %= y x = x % y Modulus
The example below shows the different results of using the different assignment operators:

Example

	<?php
	$x=10;
	echo $x; // outputs 10
	$y=20;
	$y += 100;
	echo $y; // outputs 120
	$z=50;
	$z -= 25;
	echo $z; // outputs 25
	$i=5;
	$i *= 6;
	echo $i; // outputs 30
	$j=10;
	$j /= 5;
	echo $j; // outputs 2
	$k=15;
	$k %= 4;
	echo $k; // outputs 3
	?>

PHP String Operators
Operator Name Example Result
. Concatenation $txt1 = “Hello”
$txt2 = $txt1 . ” world!” Now $txt2 contains “Hello world!”
.= Concatenation assignment $txt1 = “Hello”
$txt1 .= ” world!” Now $txt1 contains “Hello world!”
The example below shows the results of using the string operators:

Example

	<?php
	$a = "Hello";
	$b = $a . " world!";
	echo $b; // outputs Hello world!
	$x="Hello";
	$x .= " world!";
	echo $x; // outputs Hello world!
	?>

PHP Increment / Decrement Operators
Operator Name Description
++$x Pre-increment Increments $x by one, then returns $x
$x++ Post-increment Returns $x, then increments $x by one
–$x Pre-decrement Decrements $x by one, then returns $x
$x– Post-decrement Returns $x, then decrements $x by one
The example below shows the different results of using the different increment/decrement operators:

Example

	<?php
	$x=10;
	echo ++$x; // outputs 11
	$y=10;
	echo $y++; // outputs 10
	$z=5;
	echo --$z; // outputs 4
	$i=5;
	echo $i--; // outputs 5
	?>

PHP Comparison Operators
The PHP comparison operators are used to compare two values (number or string):

Operator Name Example Result
== Equal $x == $y True if $x is equal to $y
=== Identical $x === $y True if $x is equal to $y, and they are of the same type
!= Not equal $x != $y True if $x is not equal to $y
<> Not equal $x <> $y True if $x is not equal to $y
!== Not identical $x !== $y True if $x is not equal to $y, or they are not of the same type
> Greater than $x > $y True if $x is greater than $y
< Less than $x < $y True if $x is less than $y >= Greater than or equal to $x >= $y True if $x is greater than or equal to $y
<= Less than or equal to $x <= $y True if $x is less than or equal to $y The example below shows the different results of using some of the comparison operators: Example

	<?php
	$x=100;
	$y="100";
	var_dump($x == $y);
	echo "<br>";
	var_dump($x === $y);
	echo "<br>";
	var_dump($x != $y);
	echo "<br>";
	var_dump($x !== $y);
	echo "<br>";
	$a=50;
	$b=90;
	var_dump($a > $b);
	echo "<br>";
	var_dump($a < $b);
	?>

PHP Logical Operators
Operator Name Example Result
and And $x and $y True if both $x and $y are true
or Or $x or $y True if either $x or $y is true
xor Xor $x xor $y True if either $x or $y is true, but not both
&& And $x && $y True if both $x and $y are true
|| Or $x || $y True if either $x or $y is true
! Not !$x True if $x is not true

PHP Array Operators
The PHP array operators are used to compare arrays:

Operator Name Example Result
+ Union $x + $y Union of $x and $y (but duplicate keys are not overwritten)
== Equality $x == $y True if $x and $y have the same key/value pairs
=== Identity $x === $y True if $x and $y have the same key/value pairs in the same order and of the same types
!= Inequality $x != $y True if $x is not equal to $y
<> Inequality $x <> $y True if $x is not equal to $y
!== Non-identity $x !== $y True if $x is not identical to $y
The example below shows the different results of using the different array operators:

Example

	<?php
	$x = array("a" => "red", "b" => "green");
	$y = array("c" => "blue", "d" => "yellow");
	$z = $x + $y; // union of $x and $y
	var_dump($z);
	var_dump($x == $y);
	var_dump($x === $y);
	var_dump($x != $y);
	var_dump($x <> $y);
	var_dump($x !== $y);
	?>