elseif.alwaysFalse

Code example

<?php declare(strict_types = 1);

function doFoo(int $i): void
{
	$flag = 0;
	if ($i > 10) {
		echo 'big';
	} elseif ($flag) {
		echo 'unreachable';
	}
}

Why is it reported?

The elseif condition always evaluates to false, which means the branch can never be entered. This typically happens when the condition is a value that is always falsy, when it was already covered by a previous if or elseif branch, or when the types involved make the condition logically impossible. Code inside this branch is dead code and likely indicates a logic error.

In the example above, $flag is always 0 (falsy), so the elseif branch can never be entered.

How to fix it

Fix the condition so it tests something that can actually be true:

 function doFoo(int $i): void
 {
+	$flag = rand(0, 1);
 	if ($i > 10) {
 		echo 'big';
-	} elseif ($flag) {
+	} elseif ($flag === 1) {
 		// ...
 	}
 }

Or remove the unreachable branch entirely:

 function doFoo(int $i): void
 {
-	$flag = 0;
 	if ($i > 10) {
 		echo 'big';
-	} elseif ($flag) {
-		echo 'unreachable';
 	}
 }