1.2.1143. Static Loop¶
Static loop may be preprocessed.
It looks like the following loops are static : the same code is executed each time, without taking into account loop variables.
It is possible to create loops that don’t use any blind variables, though this is fairly rare. In particular, calling a method may update an internal pointer, like next() or SimpleXMLIterator\:\:`next() <https://www.php.net/next>`_.
It is recommended to turn a static loop into an expression that avoid the loop. For example, replacing the sum of all integers by the function $n * ($n + 1) / 2, or using array_sum().
This analysis doesn’t detect usage of variables with compact.
<?php
// Static loop
$total = 0;
for($i = 0; $i < 10; $i++) {
$total += $i;
}
// The above loop may be replaced by (with some math help)
$total = 10 * (10 + 1) / 2;
// Non-Static loop (the loop depends on the size of the array)
$n = count($array);
for($i = 0; $i < $n; $i++) {
$total += $i;
}
?>
1.2.1143.1. Suggestions¶
Precalculate the result of that loop and removes it altogether
Check that the loop is not missing a blind variable usage
Replace the usage of a loop with a native PHP call : for example, with str_repeat(). Although the loop is still here, it usually reflects better the intend.
1.2.1143.2. Specs¶
Short name |
Structures/StaticLoop |
Rulesets |
|
Exakat since |
0.8.4 |
PHP Version |
All |
Severity |
Minor |
Time To Fix |
Slow (1 hour) |
Precision |
High |
Features |
loop |
Available in |