1.2.68. Avoid Substr() One¶
Use array notation $string[$position] to reach a single byte in a string.
There are two ways to access a byte in a string : substr() and $v[$pos].
The second style is more readable. It may be up to four times faster, though it is a micro-optimization. It is recommended to use it.
PHP 7.1 also introduces the support of negative offsets as string index : negative offset are also reported.
Beware that substr() and $v[$pos] are similar, while mb_substr() is not. The first function works on bytes, while the latter works on characters.
<?php
$string = 'ab人cde';
echo substr($string, $pos, 1);
echo $string[$pos];
echo mb_substr($string, $pos, 1);
// when $pos = 1
// displays bbb
// when $pos = 2
// displays ??人
?>
1.2.68.1. Suggestions¶
Replace substr() with the array notations for strings.
Replace substr() with a call to mb_substr().
1.2.68.2. Specs¶
Short name |
Structures/NoSubstrOne |
Rulesets |
All, Analyze, CE, CI-checks, Changed Behavior, CompatibilityPHP71, Performances, Suggestions, Top10 |
Exakat since |
0.8.4 |
PHP Version |
All |
Severity |
Minor |
Time To Fix |
Instant (5 mins) |
Precision |
Very high |
Examples |
|
Available in |