PHP – Operators

Operators are used to perform operations on variables and values.

PHP divides the operators in the following groups:

  • Arithmetic operators
  • Assignment operators
  • Comparison operators
  • Increment/Decrement operators
  • Logical operators
  • String operators
  • Array operators

 

PHP Arithmetic Operators

 

The PHP arithmetic operators are used with numeric values to perform common arithmetical operations, such as addition, subtraction, multiplication etc.

 

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)

 

Addition Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 10;
$y = 6;

echo $x + $y;
?>

</body>
</html>

 

Output

 

 

Subtraction Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 10;
$y = 6;

echo $x – $y;
?>

</body>
</html>

 

Output

 

 

Multiplication Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 10;
$y = 6;

echo $x * $y;
?>

</body>
</html>

Output

 

 

Division Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 10;
$y = 6;

echo $x / $y;
?>

</body>
</html>

 

Output

 

 

Modulus Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 10;
$y = 6;

echo $x % $y;
?>

</body>
</html>

 

Output

 

 

Exponentiation Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 2;
$y = 8;

echo $x ** $y;
?>

</body>
</html>

 

Output

 

 

PHP Assignment Operators

 

The PHP assignment operators are used with numeric values 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

 

Equality Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 10;
echo $x;
?>

</body>
</html>

 

Output

 

 

Addition Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 20;
$x += 100;

echo $x;
?>

</body>
</html>

 

Output

 

 

Subtraction Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 50;
$x -= 30;

echo $x;
?>

</body>
</html>

 

Output

 

 

Multiplication Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 10;
$x *= 10;

echo $x;
?>

</body>
</html>

 

Output

 

 

Division Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 10;
$x /= 5;

echo $x;
?>

</body>
</html>

 

Output

 

 

Modulus Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 15;
$x %= 4;

echo $x;
?>

</body>
</html>

 

Output

 

 

PHP Comparison Operators

 

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

 

Operator Name Example Result
== Equal $x == $y Returns true if $x is equal to $y
=== Identical $x === $y Returns true if $x is equal to $y, and they are of the same type
!= Not equal $x != $y Returns true if $x is not equal to $y
<> Not equal $x <> $y Returns true if $x is not equal to $y
!== Not identical $x !== $y Returns true if $x is not equal to $y, or they are not of the same type
> Greater than $x > $y Returns true if $x is greater than $y
< Less than $x < $y Returns true if $x is less than $y
>= Greater than or equal to $x >= $y Returns true if $x is greater than or equal to $y
<= Less than or equal to $x <= $y Returns true if $x is less than or equal to $y

 

Equal Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 100;
$y = “100”;

var_dump($x == $y); // returns true because values are equal
?>

</body>
</html>

 

Output

 

 

Identical Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 100;
$y = “100”;

var_dump($x === $y); // returns false because types are not equal
?>

</body>
</html>

 

Output

 

 

Not equal Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 100;
$y = “100”;

var_dump($x != $y); // returns false because values are equal
?>

</body>
</html>

 

Output

 

 

Not equal Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 100;
$y = “100”;

var_dump($x <> $y); // returns false because values are equal
?>

</body>
</html>

 

Output

 

 

Not identical Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 100;
$y = “100”;

var_dump($x !== $y); // returns true because types are not equal
?>

</body>
</html>

 

Output

 

 

Greater than Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 100;
$y = 50;

var_dump($x > $y); // returns true because $x is greater than $y
?>

</body>
</html>

 

Output

 

 

Less than Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 10;
$y = 50;

var_dump($x < $y); // returns true because $x is less than $y
?>

</body>
</html>

 

Output

 

 

Greater than or equal to Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 50;
$y = 50;

var_dump($x >= $y); // returns true because $x is greater than or equal to $y
?>

</body>
</html>

 

Output

 

 

Less than or equal to Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 50;
$y = 50;

var_dump($x <= $y); // returns true because $x is less than or equal to $y
?>

</body>
</html>

 

Output

 

 

PHP Increment / Decrement Operators

 

The PHP increment operators are used to increment a variable’s value.

The PHP decrement operators are used to decrement a variable’s value.

 

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
Pre-increment Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 10;
echo $x++;
?>

</body>
</html>

 

Output

 

 

Post-increment Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 10;
echo ++$x;
?>

</body>
</html>

 

Output

 

 

Pre-decrement Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 10;
echo –$x;
?>

</body>
</html>

 

Output

 

 

Post-decrement Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 10;
echo $x–;
?>

</body>
</html>

 

Output

 

 

PHP Logical Operators

 

The PHP logical operators are used to combine conditional statements.

 

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

 

And Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 100;
$y = 50;

if ($x == 100 and $y == 50) {
echo “Robert Karamagi”;
}
?>

</body>
</html>

 

Output

 

Or Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 100;
$y = 50;

if ($x == 100 or $y == 80) {
echo “Robert Karamagi”;
}
?>

</body>
</html>

 

Output

 

Xor Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 100;
$y = 50;

if ($x == 100 xor $y == 80) {
echo “Robert Karamagi”;
}
?>

</body>
</html>

 

Output

 

And Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 100;
$y = 50;

if ($x == 100 && $y == 50) {
echo “Robert Karamagi”;
}
?>

</body>
</html>

 

Output

 

Or Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = 100;
$y = 50;

if ($x == 100 || $y == 80) {
echo “Robert Karamagi”;
}
?>

</body>
</html>

 

Output

 

Not Example

 

<!DOCTYPE html>

<html>
<body>

<?php
$x = 100;

if ($x !== 90) {
echo “Robert Karamagi”;
}
?>

</body>
</html>

 

Output

 

 

PHP String Operators

 

PHP has two operators that are specially designed for strings.

 

Operator Name Example Result
. Concatenation $txt1 . $txt2 Concatenation of $txt1 and $txt2
.= Concatenation assignment $txt1 .= $txt2 Appends $txt2 to $txt1

 

Concatenation Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$txt1 = “Robert”;
$txt2 = ” Karamagia”;
echo $txt1 . $txt2;
?>

</body>
</html>

 

Output

 

 

Concatenation assignment Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$txt1 = “Robert”;
$txt2 = ” Karamagi”;
$txt1 .= $txt2;
echo $txt1;
?>

</body>
</html>

 

Output

 

 

PHP Array Operators

 

The PHP array operators are used to compare arrays.

 

Operator Name Example Result
+ Union $x + $y Union of $x and $y
== Equality $x == $y Returns true if $x and $y have the same key/value pairs
=== Identity $x === $y Returns true if $x and $y have the same key/value pairs in the same order and of the same types
!= Inequality $x != $y Returns true if $x is not equal to $y
<> Inequality $x <> $y Returns true if $x is not equal to $y
!== Non-identity $x !== $y Returns true if $x is not identical to $y

 

Union Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = array(“a” => “red”, “b” => “green”);
$y = array(“c” => “blue”, “d” => “yellow”);

print_r($x + $y); // union of $x and $y
?>

</body>
</html>

 

Output

 

 

Equality Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = array(“a” => “red”, “b” => “green”);
$y = array(“b” => “green”, “a” => “red”);

var_dump($x == $y);
?>

</body>
</html>

 

Output

 

Identity Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = array(“a” => “red”, “b” => “green”);
$y = array(“b” => “green”, “a” => “red”);

var_dump($x === $y);
?>

</body>
</html>

 

Output

 

Inequality Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = array(“a” => “red”, “b” => “green”);
$y = array(“c” => “blue”, “d” => “yellow”);

var_dump($x != $y);
?>

</body>
</html>

 

Output

 

Inequality Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = array(“a” => “red”, “b” => “green”);
$y = array(“c” => “red”, “d” => “green”);

var_dump($x <> $y);
?>

</body>
</html>

 

Output

 

 

Non-identity Example

 

<!DOCTYPE html>
<html>
<body>

<?php
$x = array(“a” => “red”, “b” => “green”);
$y = array(“a” => “red”, “b” => “green”);

var_dump($x !== $y);
?>

</body>
</html>

 

Output