❔ PHP Conditional Operators – Ternary & Null Coalescing Explained

Introduction – Why Conditional Operators Matter in PHP

In PHP, conditional operators — especially the ternary operator — are shorthand tools for writing concise if-else logic. They help simplify code readability by reducing multiple lines into one.

Instead of writing:

if ($age >= 18) {
  $status = "Adult";
} else {
  $status = "Minor";
}

You can write:

$status = ($age >= 18) ? "Adult" : "Minor";

In this guide, you’ll learn:

• What conditional (ternary) operators are
• Syntax and variations
• Practical examples with explanation
• Null coalescing operator (??)
• Best practices and common pitfalls

What Are Conditional Operators in PHP?

PHP provides the following conditional operators:

Ternary Operator (?:) — Basic Syntax

(condition) ? true_expression : false_expression;

Example:

$age = 20;
$status = ($age >= 18) ? "Adult" : "Minor";
echo $status;  // Output: Adult

Explanation:

• The condition $age >= 18 is true
• So "Adult" is assigned to $status

Nested Ternary Operators

$score = 85;
$result = ($score >= 90) ? "A" : (($score >= 75) ? "B" : "C");
echo $result;  // Output: B

Explanation:

• $score is 85, not ≥ 90 → skip “A”
• Then check $score >= 75 → it’s true → assign “B”

Avoid overusing nested ternaries — they reduce readability.

Ternary Without Middle (PHP 5.3+)

PHP allows a shorthand ternary where only the true expression is written:

$username = $_GET['user'] ?: 'Guest';
echo $username;

Explanation:
If $_GET['user'] exists and is not empty, use it; otherwise, use 'Guest'.

Null Coalescing Operator (??) – PHP 7+

The ?? operator is used to check if a variable is set and not null. It’s better than using isset() manually.

Example:

$username = $_GET['user'] ?? 'Guest';
echo $username;

Explanation:
Returns 'Guest' if $_GET['user'] is not set or is null.

Safer than:

$username = isset($_GET['user']) ? $_GET['user'] : 'Guest';

Best Practices

• Use ternary operator for short and simple conditions
• Use parentheses to group logic clearly
• Use ?? for default fallbacks (e.g., form values)
• Avoid deeply nested ternary chains
• Do not over-optimize — clarity matters

Summary – Recap & Next Steps

PHP’s conditional (ternary) operators are powerful tools for writing compact conditions. While convenient, they should be used carefully to avoid sacrificing readability.

Key Takeaways:

• ?: is shorthand for if...else
• ?? handles isset() and null in one operator
• Use ternary for short decisions, not complex logic chains

Real-World Relevance:
Used in setting defaults, inline conditional rendering, fallbacks, and quick logic assignments.

Frequently Asked Questions (FAQs)

What’s the difference between ?: and ?? in PHP?
?: checks truthiness, ?? checks if a variable is set and not null.

Can I nest ternary operators in PHP?
Yes, but avoid deeply nested ternaries to maintain readability.

Is ?? faster than using isset() with ternary?
Yes. It’s faster and more readable than combining isset() with ?:.

When should I use ternary vs traditional if...else?
Use ternary for short, inline decisions; use if...else for multiple statements.