elseif.alwaysTrue - Phpstan

Code example

php

<?php declare(strict_types = 1);

function classify(int $value): string
{
	$flag = 1;
	if ($value > 0) {
		return 'positive';
	} elseif ($flag) {
		return 'zero or negative';
	} else {
		return 'unknown';
	}
}

Why is it reported?

The condition in the elseif branch always evaluates to true. This means the elseif is equivalent to a plain else, and any branches after it are unreachable. This typically indicates that the condition is redundant or that the logic does not match the developer's intent.

In the example above, $flag is always 1 (truthy), so the elseif branch is always entered when $value > 0 is false, making the else branch unreachable.

How to fix it

Replace the elseif with else if the condition is truly unnecessary:

diff-php

 <?php declare(strict_types = 1);

 function classify(int $value): string
 {
-	$flag = 1;
 	if ($value > 0) {
 		return 'positive';
-	} elseif ($flag) {
+	} else {
 		return 'zero or negative';
-	} else {
-		return 'unknown';
 	}
 }

Or write a more specific condition if different cases need to be distinguished:

diff-php

 <?php declare(strict_types = 1);

 function classify(int $value): string
 {
-	$flag = 1;
 	if ($value > 0) {
 		return 'positive';
-	} elseif ($flag) {
-		return 'zero or negative';
+	} elseif ($value === 0) {
+		return 'zero';
 	} else {
-		return 'unknown';
+		return 'negative';
 	}
 }