<?php
echo 'PHP '.PHP_VERSION.'<br>';
$qty = 1000;
$arr = array();
for ($i = 0; $i < $qty; $i++){
$arr[] = rand(-100, 100);
}
$start = microtime(true);
for ($i = 0; $i < $qty; $i++){
foreach ($arr as $v){
$v = abs($v);
}
}
echo number_format(microtime(true) - $start, 4).'<br>';
$start = microtime(true);
for ($i = 0; $i < $qty; $i++){
foreach ($arr as $v){
if ($v < 0) $v = abs($v);
}
}
echo number_format(microtime(true) - $start, 4).'<br>';
$start = microtime(true);
for ($i = 0; $i < $qty; $i++){
foreach ($arr as $v){
if ($v < 0) $v *= -1;
}
}
echo number_format(microtime(true) - $start, 4).'<br>';
?>
Result:
PHP 7.1.33
0.0910
0.0710
0.0550
Conclusion: better to check before using the feature that the number is less than zero. Even better use multiplication by -1 than this function.
abs
(PHP 4, PHP 5)
abs — Absolute value
Parametre
-
number -
The numeric value to process
Returnerings Værdier
The absolute value of number. If the
argument number is
of type float, the return type is also float,
otherwise it is integer (as float usually has a
bigger value range than integer).
Eksempler
Eksempel #1 abs() example
<?php
$abs = abs(-4.2); // $abs = 4.2; (double/float)
$abs2 = abs(5); // $abs2 = 5; (integer)
$abs3 = abs(-5); // $abs3 = 5; (integer)
?>
add a note
User Contributed Notes 1 note
eep2004 at ukr dot net ¶
3 years ago
