PHP Comparison Operators

Beginner~20 min read

Comparison operators compare two values and return a boolean result (true or false). They're essential for making decisions in your code. Understanding the difference between loose and strict comparison is crucial!

Comparison Operators Overview

Operator	Name	Example	Result
`==`	Equal	`5 == "5"`	true (loose)
`===`	Identical	`5 === "5"`	false (strict)
`!=`	Not equal	`5 != 3`	true
`<>`	Not equal	`5 <> 3`	true
`!==`	Not identical	`5 !== "5"`	true
`<`	Less than	`3 < 5`	true
`>`	Greater than	`5 > 3`	true
`<=`	Less than or equal	`5 <= 5`	true
`>=`	Greater than or equal	`5 >= 3`	true
`<=>`	Spaceship	`5 <=> 3`	1

Output

Click Run to execute your code

Loose vs Strict Comparison

Key Difference:

Loose (==, !=): Compares values after type juggling
Strict (===, !==): Compares both value AND type

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

// Loose comparison
var_dump($a == $b);   // true (values are equal after conversion)

// Strict comparison
var_dump($a === $b);  // false (different types: int vs string)
?>

Spaceship Operator (<=>) - PHP 7+

Returns -1, 0, or 1 based on comparison. Perfect for sorting!

<?php
echo 5 <=> 3;   // 1 (5 is greater)
echo 3 <=> 5;   // -1 (3 is less)
echo 5 <=> 5;   // 0 (equal)

// Useful for sorting
usort($array, function($a, $b) {
    return $a <=> $b;  // Ascending sort
});
?>

Common Mistakes

Using == instead of ===

<?php
if ($value == 0) {  // ❌ Dangerous!
    // Executes for: 0, "0", "", false, null, []
}

if ($value === 0) {  // ✅ Better
    // Only executes for integer 0
}
?>

Summary

==: Loose equality (type juggling)
===: Strict equality (type + value)
!=, <>: Not equal (loose)
!==: Not identical (strict)
<=>: Spaceship (-1, 0, 1)
Best Practice: Use === and !== by default

What's Next?

Next, we'll explore Logical Operators - combining multiple conditions with AND, OR, and NOT!

Previous Assignment Operators

Next Logical Operators