PHP Operators

In PHP, operators are symbols or keywords used to perform operations on variables and values. PHP supports a variety of operators, including arithmetic, comparison, logical, assignment, and more. Let's dive into the different categories of operators in PHP:

1. Arithmetic Operators

Arithmetic operators are used to perform mathematical operations such as addition, subtraction, multiplication, and division.

Operator	Description	Example
+	Addition	$a + $b (adds $a and $b)
-	Subtraction	$a - $b (subtracts $b from $a)
*	Multiplication	$a * $b (multiplies $a and $b)
/	Division	$a / $b (divides $a by $b)
%	Modulus (Remainder)	$a % $b (remainder when dividing $a by $b)
**	Exponentiation	$a ** $b (a raised to the power of b)

Example:

$a = 10;
$b = 3;

echo $a + $b;  // Outputs: 13
echo $a - $b;  // Outputs: 7
echo $a * $b;  // Outputs: 30
echo $a / $b;  // Outputs: 3.33333
echo $a % $b;  // Outputs: 1
echo $a ** $b; // Outputs: 1000 (10 raised to the power of 3)

2. Assignment Operators

Assignment operators are used to assign values to variables. The most common assignment operator is =, but PHP also supports combined assignment operators for arithmetic operations.

Operator	Description	Example
=	Simple assignment	$a = 5
+=	Addition assignment	$a += 5 (equivalent to $a = $a + 5)
-=	Subtraction assignment	$a -= 5 (equivalent to $a = $a - 5)
*=	Multiplication assignment	$a *= 5 (equivalent to $a = $a * 5)
/=	Division assignment	$a /= 5 (equivalent to $a = $a / 5)
%=	Modulus assignment	$a %= 5 (equivalent to $a = $a % 5)
.=	Concatenation assignment	$a .= " world" (equivalent to $a = $a . " world")

Example:

$a = 5;
$a += 3;  // $a = 5 + 3 = 8
$a -= 2;  // $a = 8 - 2 = 6
$a *= 2;  // $a = 6 * 2 = 12
$a /= 3;  // $a = 12 / 3 = 4
$a .= " world"; // $a = "4 world"

3. Comparison Operators

Comparison operators are used to compare two values. These operators return a boolean value (true or false).

Operator	Description	Example
==	Equal to	$a == $b (true if $a equals $b)
===	Identical (equal and same type)	$a === $b (true if $a equals $b and is of the same type)
!=	Not equal to	$a != $b (true if $a is not equal to $b)
!==	Not identical	$a !== $b (true if $a is not equal to $b or not the same type)
>	Greater than	$a > $b (true if $a is greater than $b)
<	Less than	$a < $b (true if $a is less 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)

Example:

$a = 5;
$b = 3;

var_dump($a == $b);  // Outputs: bool(false)
var_dump($a != $b);  // Outputs: bool(true)
var_dump($a > $b);   // Outputs: bool(true)
var_dump($a < $b);   // Outputs: bool(false)
var_dump($a === 5);  // Outputs: bool(true)
var_dump($a !== '5'); // Outputs: bool(true)

4. Logical Operators

Logical operators are used to combine multiple conditions and return a boolean value.

Operator	Description	Example
&&	And (true if both sides are true)	$a && $b (true if both $a and $b are true)
`		`
!	Not (true if the condition is false)	!$a (true if $a is false)
and	Logical AND (same as &&)	$a and $b (true if both $a and $b are true)
or	Logical OR (same as `

Example:

$a = true;
$b = false;

var_dump($a && $b);  // Outputs: bool(false)
var_dump($a || $b);  // Outputs: bool(true)
var_dump(!$a);       // Outputs: bool(false)

5. Increment/Decrement Operators

Increment and decrement operators are used to increase or decrease a variable's value by 1.

Operator	Description	Example
++	Increment (adds 1 to the value)	$a++ or ++$a (increases $a by 1)
--	Decrement (subtracts 1 from the value)	$a-- or --$a (decreases $a by 1)

• Post-increment ($a++): Increases the value of $a after the expression is evaluated.
• Pre-increment (++$a): Increases the value of $a before the expression is evaluated.

Example:

$a = 5;

echo $a++;  // Outputs: 5 (then $a becomes 6)
echo ++$a;  // Outputs: 7 (before the expression is evaluated, $a becomes 7)

6. String Operators

PHP also has a special operator for string manipulation.

Operator	Description	Example
.	Concatenation	$a . $b (concatenates $a and $b)
.=	Concatenation assignment	$a .= $b (appends $b to $a)

Example:

$a = "Hello";
$b = "World";

echo $a . " " . $b;  // Outputs: Hello World

$a .= $b;  // Appends $b to $a
echo $a;   // Outputs: HelloWorld

7. Array Operators

Array operators are used to perform operations on arrays.

Operator	Description	Example
+	Union of two arrays	$a + $b (returns array $a merged with array $b)
==	Equality (true if arrays are equal)	$a == $b (true if $a and $b have the same keys and values)
===	Identity (true if arrays are identical)	$a === $b (true if $a and $b have the same keys, values, and order)
!=	Inequality	$a != $b (true if $a and $b are not equal)
!==	Non-identity	$a !== $b (true if $a and $b are not identical)

Example:

$a = [1, 2, 3];
$b = [1, 2, 3];

var_dump($a == $b);  // Outputs: bool(true)
var_dump($a === $b); // Outputs: bool(true)

$c = [1, 2];
$d = [1, 2, 3];

var_dump($c + $d);   // Outputs: array(1, 2, 3) (array $d's elements are merged)

8. Ternary Operator

The ternary operator is a shorthand for the if-else statement. It is used to return one of two values depending on a condition.

Syntax:

condition ? value_if_true : value_if_false;

Example:

$a = 5;
echo $a > 3 ? 'Greater' : 'Smaller';  // Outputs: Greater

Conclusion

• PHP operators are crucial for performing a variety of tasks, such as arithmetic, comparison, logical operations, string manipulation, and more.
• Understanding these operators is essential for building dynamic and functional PHP applications.
• You can combine these operators to create complex expressions and control the flow of your application logic.