Unreachable Code¶
Unreachable code refers to a section of code within a program that can never be executed during the program’s runtime. It means that the code is written in such a way that it can never be reached or accessed by the program’s execution flow.
Unreachable code can occur due to several reasons:
Conditional statements
Early return statements
Infinite loops
Branching with goto, yield, break, return, die…
<?php
$a = 1;
echo foo($a);
exit;
// This is unreachable code, as it will never be executed
echo $a;
// This is not unreachable, as PHP scoops the definition at linting time
function foo($s) {
return strtolower($s);
}
?>