if...else Statements
Run different code depending on whether a condition is true.
Syntax
if (condition) {
// code
} elseif (condition) {
// code
} else {
// code
}Conditional statements let your script make decisions.
if— run a block if a condition is true.if...else— run one block or another.if...elseif...else— test several conditions in order.
Example
Loading editor…
Press Run to execute the code.
When to use it
- Redirect unauthenticated users to the login page only when the session contains no user ID.
- Display a different discount message based on whether a customer's cart total exceeds a threshold.
- Show a 'Your account is suspended' banner when a user's status flag equals 'banned'.
More examples
Basic if / else
The simplest branch: one path when the condition is true, another when it is false.
<?php
$balance = 120;
if ($balance >= 100) {
echo 'Premium tier';
} else {
echo 'Standard tier';
}if / elseif / else chain
elseif chains test conditions in order; the first true branch runs and the rest are skipped.
<?php
$score = 74;
if ($score >= 90) {
echo 'A';
} elseif ($score >= 75) {
echo 'B';
} elseif ($score >= 60) {
echo 'C';
} else {
echo 'F';
}Nested if for multi-factor checks
Nested ifs separate independent conditions, here distinguishing authentication from authorisation.
<?php
$isLoggedIn = true;
$isAdmin = false;
if ($isLoggedIn) {
if ($isAdmin) {
echo 'Admin dashboard';
} else {
echo 'User dashboard';
}
} else {
header('Location: /login');
exit;
}
Discussion