note 93624 deleted from types.comparisons by danbrown
| From: | danbrown@php.net | Date: | Fri, 18 Sep 2009 19:54:16 +0000 |
| Subject: | note 93624 deleted from types.comparisons by danbrown | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-160848@lists.php.net to get a copy of this message | ||
Note Submitter: Michael
----
The following two conditional statements are identical:
<?php
if ($foo) {
...
}
if (!empty($foo)) {
...
}
?>
...as are the following:
<?php
if (!$foo) {
...
}
if (empty($foo)) {
...
}
?>
However, checking to see if a variable is empty is (very slightly) quicker than checking to see if a
variable is false, and checking to see if a variable is true is (very slightly) quicker than
checking to see if a variable is not empty:
<?php
// Create the array
$awesome = array();
// Populate the array with FALSE
for ($i = 0; $i <= 1000000; $i++) {
$awesome[$i] = false;
}
// Check to see if the value is true
$one = microtime(true);
foreach ($awesome as $foo) {
if ($foo) {
return true;
}
}
$two = microtime(true);
$bar1 = $two - $one;
// Check to see if the value is not empty
$one = microtime(true);
foreach ($awesome as $foo) {
if (!empty($foo)) {
return true;
}
}
$two = microtime(true);
$bar2 = $two - $one;
// Populate the array with TRUE
for ($i = 0; $i <= 1000000; $i++) {
$awesome[$i] = true;
}
// Check to see if the value is false
$one = microtime(true);
foreach ($awesome as $foo) {
if (!$foo) {
return true;
}
}
$two = microtime(true);
$bar3 = $two - $one;
// Check to see if the value is empty
$one = microtime(true);
foreach ($awesome as $foo) {
if (empty($foo)) {
return true;
}
}
$two = microtime(true);
$bar4 = $two - $one;
print_r($bar1); // 0.0960810184478 (TRUE)
print_r($bar2); // 0.1212460994720 (NOT EMPTY)
print_r($bar3); // 0.1063888072967 (FALSE)
print_r($bar4); // 0.1030158996582 (EMPTY)
?>