PHP If-Else and Switch: Making Decisions in Your Code

What is it?

Conditional statements let your program make decisions at runtime based on whether a condition is true or false.

Why does it matter?

Almost every feature in software involves a decision: is the user logged in? Is the payment valid? Is the stock available? Without conditionals none of this is possible.

Master PHP conditional statements — if, else, elseif, and switch with practical examples.

Real-World Use Cases

🔐 User authentication - Check if a session exists and redirect to login if not — the most common if-else pattern in PHP.
🎓 Grading systems - Assign letter grades based on marks ranges using elseif chains — perfect for ordered conditions.
📦 Order status display - Use switch to map status codes like 'pending', 'shipped', 'delivered' to human-readable labels.
💳 Payment gateway routing - Route to different payment processors based on currency or region using if-elseif blocks.

if-else and elseif

<!--?php
$marks = 75;
if ($marks -->= 90)      echo 'Grade: A';
elseif ($marks >= 75)  echo 'Grade: B';
elseif ($marks >= 60)  echo 'Grade: C';
else                   echo 'Grade: F';
// Output: Grade: B

Ternary and Null Coalescing

<!--?php
$age    = 20;
$status = ($age -->= 18) ? 'Adult' : 'Minor';
echo $status;  // Adult

// Null coalescing — perfect for missing form fields
$user = $_GET['name'] ?? 'Guest';
echo $user;  // Guest if name not in URL

Q: When should I use switch instead of if-elseif?

Use switch when comparing one variable against many fixed values. Use if-elseif for ranges or complex conditions involving multiple variables.