website/errors/booleanOr.resultUnused.md
<?php declare(strict_types = 1);
function doFoo(bool $a, bool $b): void
{
$a || $b;
}
The result of the || (boolean OR) operator is computed but never used. The expression is evaluated as a standalone statement, meaning its result is discarded. This is usually a mistake -- either the result should be assigned to a variable, returned, or used in a condition.
A common cause of this error is confusing || with or. The or operator has lower precedence, which can lead to unexpected behaviour when mixed with assignment.
Assign the result to a variable if it is needed:
<?php declare(strict_types = 1);
function doFoo(bool $a, bool $b): void
{
- $a || $b;
+ $result = $a || $b;
}
Or use the expression as a condition:
<?php declare(strict_types = 1);
function doFoo(bool $a, bool $b): void
{
- $a || $b;
+ if ($a || $b) {
+ // do something
+ }
}
If the intent was to call a function when $a is falsy, consider using an explicit if statement instead:
<?php declare(strict_types = 1);
-function doFoo(bool $a, bool $b): void
+function doFoo(bool $a): void
{
- $a || $b;
+ if (!$a) {
+ doSomething();
+ }
}