Operator Types - Go4Expert Tutorials

PHP language provides us with a range of operators which allow us to perform diverse operations or actions on variables or values. These variables or values on which the operator performs actions are called operands.

For example, the addition symbol (+) is an operator that instructs PHP to add two variables or values, while the greater than symbol is an operator that instructs PHP to compare two values.

All PHP operators can be grouped into the following categories depending on the type of operation performed using them:

Arithmetic Operators
Assignment Operators
Comparison Operators
Increment/Decrement Operators
Logical Operators
String Concatenation Operators
Array Operators

PHP Arithmetic Operators

Arithmetic operators can be used to perform common arithmetical operations, such as addition, subtraction, multiplication and so on with numerical variables and values. The following table shows the complete list of PHP's arithmetic operators:

Operator	Name	Example	Result
+	Addition	$a + $b	Sum of $a and $b
-	Subtraction	$a - $b	Difference of $a and $b
*	Multiplication	$a * $b	Product of $a and $b
/	Division	$a / $b	Quotient of $a and $b
%	Modulus	$a % $b	Remainder of $a divided by $b
**	Exponentiation	$a**$b	Raising $a to the power of $b

The following example shows us how arithmetic operators can be used while programming in PHP.

Example :

Code:

<?php
$x = 10;
$y = 4;
echo($x + $y); // 0utputs: 14
$z=$x - $y;
echo($z); // 0utputs: 6
$z=$x * $y;
echo($z); // 0utputs: 40
$z=$x / $y;
echo($z);
// 0utputs: 2.5
echo($x % $y); // 0utputs: 2
?>

PHP Assignment Operators

Assignment operators are used with numerical values to assign values to variables. The assignment operator is “=”. When it is used with numerical values the operand on the left gets assigned the value of the expression on the right. However it has a different meaning when it is used with strings.

Operator	Name	Example	Result
=	Assign	$a = $b	$a = $b
+=	Add and assign	$a += $b	$a = $a + $b
-=	Subtract and assign	$a -= $b	$a = $a - $b
*=	Multiply and assign	$a *= $b	$a = $a * $b
/=	Divide and assign - Quotient	$a /= $b	$a = $a / $b
%=	Divide and assign - Modulus	$a %= $b	$a = $a % $b

The following example which shows assignment operators in action

Example:

Code:

<?php
$a = 10;
echo $a; // Outputs: 10
$a = 20;
$a += 30;
echo $a; // Outputs: 50
$a = 60;
$a -= 20;
echo $a ; // Outputs: 40
$a = 5;
$a *= 20;
echo $a; // Outputs: 100
$a = 50;
$a /= 10;
echo $a; // Outputs: 5
$a = 100;
$a %= 15;
echo $a; // Outputs: 10
?>

PHP Comparison Operators

The Comparison Operators are used to compare any two values which could be a string or a number. Comparison operators are generally used to control the flow of the program.

Operator	Name	Example	Result
==	Equal	$a == $b	True - if $a is equal to $b
===	Identical	$a === $b	True only if $a is equal to $b and a & b are of the same type
!=	Not equal	$a != $b	True - if $a is not equal to $b
><	Not equal	$a><$b	True - if $a is not equal to $b
!==	Not identical	$a !== $b	True - if $a is not equal to $b, or they are not of the same type
<	Less than	$a < $b	True if $a is less than $b
>	Greater than	$a > $b	True if $a is greater than $b
>=	Greater than or equal to	$a >= $b	True if $a is greater than or equal to $b
<=	Less than or equal to	$a <= $b	True if $a is less than or equal to $b

Comparison operators help us compare two values in a Boolean manner.

Example:

Code:

<?php
$a = 25;
$b = 35;
$c = "25";
var_col($a == $c);
// Outputs: boolean true
var_ col ($a === $c);
// Outputs: boolean false
var_ col ($a != $b);
// Outputs: boolean true
var_ col ($a !== $c);
// Outputs: boolean true
var_ col ($a $b);
// Outputs: boolean false
var_ col ($a = $b);
// Outputs: boolean false
?>

PHP Comparison Operators

The Comparison Operators are used to compare any two values which could be a string or a number.

Operator	Name	Effect
++$a	Pre-increment	Increments $a by one, then returns $a
$a++	Post-increment	Returns $a, then increments $a by one
--$a	Pre-decrement	Decrements $a by one, then returns $a
$a--	Post-decrement	Returns $a, then decrements $a by one

The following example shows the practical usage of the increment and decrement operators.

Example:

Code:

<?php
$a = 20;
echo ++$a; // Outputs: 21
echo $a; // Outputs: 21
$a = 20;
echo $a++;
// Outputs: 20
echo $a;
// Outputs: 21
$a = 20;
echo --$a;
// Outputs: 19
echo $a;
// Outputs: 19
$x = 20;
echo $x--;
// Outputs: 20
echo $x;
// Outputs: 19
?>

PHP Logical Operators

Logical operators are generally used to combine conditional statements.

Operator	Name	Example	Result
And	And	$a and $b	True if both $a and $b are true
Or	Or	$a or $b	True if either $a or $b is true
Xor	Xor	$a xor $b	True if either $a or $b is true, but not both
&&	And	$a && $b	True if both $a and $b are true
\|\|	Or	$a \|\| $b	True if either $$a or $b is true
!	Not	!$a	True if $a is not true

The following example shows these logical operators in action:

Example:

Code: 
<?php
$year = 2018;
// Leap years are divisible by 400 or by 4 but not 100
if(($year % 400 == 0) || (($year % 100 != 0) && ($year % 4 == 0))){
    echo "$year is a leap year.";
}
else{
    echo "$year is not a leap year.";
}
?>

PHP Array Operators

Array operators are operators which allow us to perform union and high level comparison operations on arrays.

Operator	Name	Example	Result
+	Union	$a + $b	Union of $a and $b
==	Equality	$a == $b	Appends $string2 to $string1

The following example shows you these string operators in action

Example:

Code:

<?php
$x = "Hello";
$y = " World!";
echo $x . $y; // Outputs: Hello my World!
$x .= $y;
echo $x; // Outputs: Hello my World!
?>

PHP Array Operators

Array operators are operators which allow us to perform union and high level comparison operations on arrays.

Operator	Name	Example	Result
+	Union	$a + $b	Union of $a and $b
==	Equality	$a == $b	True if $a and $b have the same key/value pairs
===	Identity	$a === $b	True if $a and $b have the same key/value pairs in the same order and of the same types
!=	Inequality	$a != $b	True if $a is not equal to $b
	Inequality	$a $b	True if $a is not equal to $b
!==	Non-identity	$a !== $b	True if $a is not identical to $b

Below example shows these array operators in action

Example :

Code:

<?php
$x = array("a" => "Red", "b" => "Green", "c" => "Blue");
$y = array("u" => "Yellow", "v" => "Orange", "w" => "Pink");
$z = $x + $y; // Union of $x and $y
var_dmp($z);
var_dmp($x == $y); // Outputs: boolean false
var_dmp($x === $y); // Outputs: boolean false
var_dmp($x != $y); // Outputs: boolean true
var_dmp($x $y); // Outputs: boolean true
var_dmp($x !== $y); // Outputs: boolean true
?>