PHP Operators

PHP Operators – Types, Examples & Usage Guide

Operators are symbols or keywords in PHP that perform actions on values, like calculations, comparisons, or logic tasks.

1. Arithmetic Operators

Used for mathematical calculations.

Operator	Description	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 `$b`
`%`	Modulus (remainder)	`$a % $b`	Remainder of `$a` divided by `$b`
`**`	Exponentiation	`$a ** $b`	`$a` raised to the power of `$b`

Example:

<?php
$a = 21;
$b = 4;
echo $a + $b; // Outputs: 25
echo $a % $b; // Outputs: 1
?>

2. Assignment Operators

Used to assign values to variables.

Operator	Example	Equivalent
`=`	`$a = $b`	`$a = $b`
`+=`	`$a += $b`	`$a = $a + $b`
`-=`	`$a -= $b`	`$a = $a - $b`
`*=`	`$a *= $b`	`$a = $a * $b`
`/=`	`$a /= $b`	`$a = $a / $b`
`%=`	`$a %= $b`	`$a = $a % $b`

Example:

<?php
$a = 5;
$a += 10; // Equivalent to $a = $a + 10
echo $a;  // Outputs: 15
?>

3. Comparison Operators

Used to compare two values. They return a boolean value (true or false).

Operator	Description	Example	Result
`==`	Equal	`$a == $b`	`true` if `$a` is equal to `$b`
`===`	Identical (equal and same type)	`$a === $b`	`true` if `$a` equals `$b` and both are of the same type
`!=`	Not equal	`$a != $b`	`true` if `$a` is not equal to `$b`
`<>`	Not equal	`$a <> $b`	Same as `!=`
`!==`	Not identical	`$a !== $b`	`true` if `$a` is not equal or not the same type as `$b`
`>`	Greater than	`$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 `$b`
`<=>`	Spaceship (PHP 7+)	`$a <=> $b`	Returns `-1`, `0`, or `1`

Example:

<?php
$a = 5;
$b = 10;
echo $a < $b; // Outputs: 1 (true)
echo $a === "5"; // Outputs:  (false, different types)
?>

4. Logical Operators

Used for logical operations.

Operator	Description	Example	Result
`&&`	And	`$a && $b`	`true` if both `$a` and `$b` are true
`		`	Or
`!`	Not	`!$a`	`true` if `$a` is false
`and`	And (lower priority)	`$a and $b`	Same as `&&`
`or`	Or (lower priority)	`$a or $b`	Same as `

Example:

<?php
$a = true;
$b = false;
echo $a && $b; // Outputs:  (false)
echo $a || $b; // Outputs: 1 (true)
?>

5. Increment/Decrement Operators

Used to increase or decrease the value of a variable.

Operator	Description	Example
`++$a`	Pre-increment	Increases `$a` by 1, then returns `$a`
`$a++`	Post-increment	Returns `$a`, then increases `$a` by 1
`--$a`	Pre-decrement	Decreases `$a` by 1, then returns `$a`
`$a--`	Post-decrement	Returns `$a`, then decreases `$a` by 1

Example:

<?php
$a = 6;
echo ++$a; // Outputs: 7 (pre-increment)
echo $a--; // Outputs: 7 (post-decrement)
echo $a;   // Outputs: 6
?>

6. String Operators

Used to manipulate strings.

Operator	Description	Example	Result
`.`	Concatenation	`$a . $b`	Combines `$a` and `$b`
`.=`	Concatenation assignment	`$a .= $b`	Appends `$b` to `$a`

Example:

<?php
$a = "Hello";
$b = " World";
echo $a . $b; // Outputs: Hello World
$a .= $b;
echo $a;      // Outputs: Hello World
?>

7. Array Operators

Used to compare or manipulate arrays.

Operator	Description	Example	Result
`+`	Union	`$a + $b`	Combines `$a` and `$b`
`==`	Equality	`$a == $b`	`true` if `$a` and `$b` have the same key-value pairs
`===`	Identity	`$a === $b`	`true` if `$a` and `$b` are identical
`!=`	Inequality	`$a != $b`	`true` if `$a` and `$b` are not equal
`<>`	Inequality	`$a <> $b`	Same as `!=`
`!==`	Non-identity	`$a !== $b`	`true` if `$a` and `$b` are not identical

Example:

<?php
$a = array("x" => 1, "y" => 2);
$b = array("z" => 3, "x" => 1);
$c = $a + $b; // Union
print_r($c);
// Outputs: Array ( [x] => 1 [y] => 2 [z] => 3 )
?>