offsetExists($index) examines the cache, not the inner or outer iterator.
<?php
$cache = new \CachingIterator(
new \ArrayIterator(['a', 'b', 'c', 'd']),
\CachingIterator::FULL_CACHE);
$shortRange = range(0, 1);
$fullRange = range(0, 3);
foreach ($shortRange as $index) {
$cache->next();
}
echo PHP_EOL . 'The cache' . PHP_EOL;
var_export($cache->getCache());
echo PHP_EOL;
foreach ($fullRange as $offset) {
print_r("cache offset '$offset' " .
($cache->offsetExists("$offset") == 1
? 'exists'
: "doesn't exist"
) . PHP_EOL);
}
?>
The cache
array (
0 => 'a',
1 => 'b',
)
cache offset '0' exists
cache offset '1' exists
cache offset '2' doesn't exist
cache offset '3' doesn't exist
CachingIterator::offsetExists
(PHP 5 >= 5.2.0, PHP 7, PHP 8)
CachingIterator::offsetExists — The offsetExists purpose
参数
-
key -
The index being checked.
返回值
Returns true if an entry referenced by the offset exists, false otherwise.
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User Contributed Notes 1 note
ddrake at dreamingmind dot com ¶
4 years ago
