Operators in PHP

Overview

Operators in PHP are used to perform various operations on variables and values. PHP supports different types of operators, including arithmetic, assignment, comparison, logical, and more. Understanding these operators is crucial for performing basic operations and controlling the flow of your PHP scripts.

In this section, we will cover the following types of operators:

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

Arithmetic Operators

Arithmetic operators are used to perform basic mathematical operations.

Operator	Description	Example
+	Addition	$a + $b
-	Subtraction	$a - $b
*	Multiplication	$a * $b
/	Division	$a / $b
%	Modulus (remainder)	$a % $b
**	Exponentiation (since PHP 5.6)	$a ** $b

Example:

<?php
$a = 10;
$b = 5;

echo $a + $b;  // Output: 15
echo $a - $b;  // Output: 5
echo $a * $b;  // Output: 50
echo $a / $b;  // Output: 2
echo $a % $b;  // Output: 0
echo $a ** $b; // Output: 100000
?>

Assignment Operators

Assignment operators are used to assign values to variables.

Operator	Description	Example
=	Assigns the right-hand value to the left-hand variable	$a = $b
+=	Adds right-hand value to the left-hand variable	$a += $b (equivalent to $a = $a + $b)
-=	Subtracts right-hand value from the left-hand variable	$a -= $b (equivalent to $a = $a - $b)
*=	Multiplies left-hand variable by the right-hand value	$a *= $b (equivalent to $a = $a * $b)
/=	Divides left-hand variable by the right-hand value	$a /= $b (equivalent to $a = $a / $b)
%=	Assigns the remainder of left-hand variable divided by right-hand value	$a %= $b (equivalent to $a = $a % $b)

Example:

<?php
$a = 10;
$a += 5; // $a is now 15
$a -= 3; // $a is now 12
$a *= 2; // $a is now 24
$a /= 4; // $a is now 6
?>

Comparison Operators

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

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

Example:

<?php
$a = 5;
$b = 10;

var_dump($a == $b);  // Output: bool(false)
var_dump($a != $b);  // Output: bool(true)
var_dump($a < $b);   // Output: bool(true)
var_dump($a === "5");  // Output: bool(false)
?>

Logical Operators

Logical operators are used to combine multiple conditions or boolean expressions.

Operator	Description	Example
&&	Logical AND (true if both conditions are true)	$a && $b
`		`
!	Logical NOT (inverts the condition)	!$a

Example:

<?php
$a = true;
$b = false;

var_dump($a && $b);  // Output: bool(false)
var_dump($a || $b);  // Output: bool(true)
var_dump(!$a);       // Output: bool(false)
?>

Increment and Decrement Operators

Increment and Decrement operators are used to increase or decrease the value of a variable by 1.

Operator	Description	Example
++	Increment (increase by 1)	$a++ (post-increment) or ++$a (pre-increment)
--	Decrement (decrease by 1)	$a-- (post-decrement) or --$a (pre-decrement)

Example:

<?php
$a = 5;
echo $a++;  // Output: 5 (Post-increment: value is used first, then incremented)
echo ++$a;  // Output: 7 (Pre-increment: value is incremented first, then used)

$b = 10;
echo $b--;  // Output: 10 (Post-decrement)
echo --$b;  // Output: 8 (Pre-decrement)
?>

String Operators

String operators are used to manipulate strings.

Operator	Description	Example
.	Concatenation (combine two strings)	$a . $b
.=	Concatenate and assign	$a .= $b

Example:

<?php
$greeting = "Hello";
$name = "Lucy";

echo $greeting . " " . $name;  // Output: Hello Lucy
$greeting .= " there!";        // $greeting is now "Hello there!"
?>

Array Operators

Array operators are used to perform operations on arrays.

Operator	Description	Example
+	Union (combines two arrays)	$array1 + $array2
==	Equality (returns true if arrays have the same key/value pairs)	$array1 == $array2
===	Identity (returns true if arrays have the same key/value pairs in the same order)	$array1 === $array2
!=	Inequality (returns true if arrays are not equal)	$array1 != $array2
!==	Non-identity (returns true if arrays are not identical)	$array1 !== $array2

Example:

<?php
$array1 = array("a" => "apple", "b" => "banana");
$array2 = array("a" => "apple", "b" => "banana");

var_dump($array1 == $array2);  // Output: bool(true)
var_dump($array1 === $array2); // Output: bool(true)
?>

Conclusion

In this section, we explored the various types of operators in PHP, including arithmetic, assignment, comparison, logical, increment/decrement, string, and array operators. These operators allow you to manipulate variables and control the flow of your code. Understanding and utilizing these operators is fundamental to writing efficient and functional PHP scripts.

In the next section, we will dive deeper into control structures like conditionals and loops to further enhance your PHP skills.