1.2.1286. Unset In Foreach

Unset applied to the variables of a foreach loop are useless. Those variables are copies and not the actual value. Even if the value is a reference, unsetting it has no effect on the original array : the only effect may be indirect, on elements inside an array, or on properties inside an object.

<?php

// When unset is useless
$array = [1, 2, 3];
foreach($array as $a) {
    unset($a);
}

print_r($array); // still [1, 2, 3]

foreach($array as $b => &$a) {
    unset($a);
}

print_r($array); // still [1, 2, 3]

// When unset is useful
$array = [ [ 'c' => 1] ]; // Array in array
foreach($array as &$a) {
    unset(&$a['c']);
}

print_r($array); // now [ ['c' => null] ]

?>

1.2.1286.1. Connex PHP features

1.2.1286.1.1. Suggestions

  • Drop the unset

1.2.1286.1.2. Specs

Short name

Structures/UnsetInForeach

Rulesets

All, Analyze, Changed Behavior, Dead code

Exakat since

0.8.4

PHP Version

All

Severity

Major

Time To Fix

Quick (30 mins)

Precision

Very high

Available in

Entreprise Edition, Exakat Cloud