Home Tutorials Videos Q&A MCQ Shortcuts Exercises Appointment Login
Lesson 9 of 50 – PHP Operators
18%

PHP Operators

Operators are symbols used to perform operations on variables and values. PHP supports arithmetic, assignment, comparison, logical, increment/decrement, string, array and other operators.

1. Arithmetic Operators

Arithmetic operators perform mathematical calculations.

Operator Meaning Example
+ Addition 10 + 5 = 15
- Subtraction 10 - 5 = 5
* Multiplication 10 * 5 = 50
/ Division 10 / 5 = 2
% Modulus (remainder) 10 % 3 = 1
** Exponentiation 2 ** 3 = 8

Example:

<?php
$a = 10;
$b = 3;

echo $a + $b;
echo "<br>";
echo $a - $b;
echo "<br>";
echo $a * $b;
echo "<br>";
echo $a / $b;
echo "<br>";
echo $a % $b;
echo "<br>";
echo $a ** $b;
?>

Output:

13
7
30
3.3333333333333
1
1000

Remember: the modulus operator returns the remainder after division.

2. Assignment Operators

Assignment operators assign values to variables or update their existing values.

Operator Example Equivalent operation
= $x = 10 Assign 10 to $x
+= $x += 5 $x = $x + 5
-= $x -= 5 $x = $x - 5
*= $x *= 2 $x = $x * 2
/= $x /= 2 $x = $x / 2
%= $x %= 3 $x = $x % 3

Example:

<?php
$x = 10;

$x += 5;
echo $x;
echo "<br>";

$x -= 3;
echo $x;
echo "<br>";

$x *= 2;
echo $x;
?>

Output:

15
12
24
3. Comparison Operators

Comparison operators compare two values. They generally return a Boolean result: true or false.

Operator Meaning
== Equal in value after type conversion if needed
=== Identical in value and type
!= Not equal
!== Not identical in value or type
> Greater than
< Less than
>= Greater than or equal to
<= Less than or equal to

Example:

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

var_dump($a == $b);
echo "<br>";

var_dump($a === $b);
echo "<br>";

var_dump($a != 5);
echo "<br>";

var_dump($a > 5);
?>

Output:

bool(true)
bool(false)
bool(true)
bool(true)

The == operator compares values with possible type conversion. The === operator also requires the types to match.

4. Logical Operators

Logical operators combine or reverse conditions. They are commonly used with if statements.

Operator Meaning
&& True when both conditions are true
|| True when at least one condition is true
! Reverses a Boolean value
and Logical AND with lower precedence than &&
or Logical OR with lower precedence than ||
xor True when exactly one operand is true

Example using &&:

<?php
$age = 20;
$hasId = true;

if ($age >= 18 && $hasId) {
    echo "Entry allowed";
} else {
    echo "Entry denied";
}
?>

Output:

Entry allowed

Example using ||:

<?php
$day = "Sunday";

if ($day == "Saturday" || $day == "Sunday") {
    echo "Holiday";
} else {
    echo "Working day";
}
?>

Output:

Holiday
5. Increment and Decrement Operators

Increment operators increase a variable's value by one. Decrement operators decrease it by one.

Operator Meaning
++$x Increment first, then use the value
$x++ Use the value first, then increment
--$x Decrement first, then use the value
$x-- Use the value first, then decrement

Example:

<?php
$x = 5;

echo ++$x;
echo "<br>";

echo $x++;
echo "<br>";

echo $x;
echo "<br>";

echo --$x;
?>

Output:

6
6
7
6

Prefix changes the value before using it. Postfix uses the current value before changing it.

6. String Operators

PHP provides the dot operator (.) to concatenate strings, meaning to join them together.

Example:

<?php
$firstName = "Rahul";
$lastName = "Kumar";

$fullName = $firstName . " " . $lastName;

echo $fullName;
?>

Output:

Rahul Kumar

The .= operator appends text to an existing string. 

<?php
$message = "Welcome";
$message .= " to PHP";

echo $message;
?>

Output:

Welcome to PHP
7. Conditional (Ternary) Operator

The ternary operator is a short way to choose between two values based on a condition.

Syntax:

condition ? value_if_true : value_if_false;

Example:

<?php
$marks = 75;

$result = ($marks >= 40) ? "Pass" : "Fail";

echo $result;
?>

Output:

Pass

If the condition is true, the first value is selected. Otherwise, the second value is selected.

8. Null Coalescing and Spaceship Operators

Null coalescing operator (??)

It returns the left-hand value if it exists and is not null; otherwise, it returns the right-hand value. 

<?php
$username = null;

$name = $username ?? "Guest";

echo $name;
?>

Output:

Guest

Spaceship operator (<=>)

It compares two values and returns -1, 0, or 1. 

<?php
echo 5 <=> 10;
echo "<br>";

echo 10 <=> 10;
echo "<br>";

echo 15 <=> 10;
?>

Output:

-1
0
1

A negative result means the left value is smaller, zero means the values compare equal, and a positive result means the left value is greater.

9. Array Operators and Operator Precedence

PHP also supports operators for comparing and combining arrays.

Array union (+):

<?php
$a = ["name" => "Rahul", "age" => 20];
$b = ["city" => "Patna", "age" => 25];

$result = $a + $b;

print_r($result);
?>

Output:

Array
(
    [name] => Rahul
    [age] => 20
    [city] => Patna
)

The array union operator keeps all keys from the left-hand array. When a key exists in both arrays, the left-hand value is retained.

Operator precedence:

Operator precedence determines which operation is performed first. Parentheses can make the intended order clear. 

<?php
$result1 = 5 + 3 * 2;
$result2 = (5 + 3) * 2;

echo $result1;
echo "<br>";
echo $result2;
?>

Output:

11
16

Multiplication is performed before addition in the first expression. Parentheses change the order in the second expression.

📝 Practical Assignment

Write PHP programs to complete these exercises:

  1. Add two numbers using the + operator.
  2. Calculate the remainder when 25 is divided by 4.
  3. Compare two numbers using == and ===.
  4. Check whether a student has passed using the && operator.
  5. Check whether a day is Saturday or Sunday using ||.
  6. Join your first name and last name using the dot operator.
  7. Use the ternary operator to check whether a number is positive or not.
  8. Use ?? to provide a default username when the variable is null.

Sample starting code:

<?php
$a = 25;
$b = 4;

echo "Addition: " . ($a + $b);
echo "<br>";
echo "Remainder: " . ($a % $b);
echo "<br>";

$marks = 65;

$result = ($marks >= 40) ? "Pass" : "Fail";

echo $result;
?>

🧠 Quick Quiz

1. Which operator is used for exponentiation in PHP?



2. What is the result of 10 % 3?



3. Which operator joins strings in PHP?



← Previous Next →