The PHP CachingIterator::getCache API performs a focused operation on an object or value. The examples below show its effect on actual data.
Returns the entries retained by CachingIterator when FULL_CACHE is enabled.
What Is CachingIterator::getCache in PHP?
Returns the entries retained by CachingIterator when FULL_CACHE is enabled.
Syntax:
CachingIterator::getCache()
This operation has no parameters.
Return type declared by PHP: mixed / not explicitly declared. The value or side effect is demonstrated in the examples below.
Example 1: Basic Usage
This example uses a small input to make the main behavior visible.
<?php
$cachingIterator = new CachingIterator(new ArrayIterator(["pear" => 4, "apple" => 2, "plum" => 9]), CachingIterator::FULL_CACHE);
foreach ($cachingIterator as $item) {}
print_r($cachingIterator->getCache());
Output:
Array
(
[pear] => 4
[apple] => 2
[plum] => 9
)
Returns the entries retained by CachingIterator when FULL_CACHE is enabled.
Example 2: A Different Input
A different set of values shows the same operation in another situation.
<?php
$cachingIterator = new CachingIterator(new ArrayIterator(["first" => "draft", "second" => "ready", "third" => "done"]), CachingIterator::FULL_CACHE);
foreach ($cachingIterator as $item) {}
print_r($cachingIterator->getCache());
Output:
Array
(
[first] => draft
[second] => ready
[third] => done
)
The cache is populated during traversal and is not automatically complete at construction.
Practical Example: Applying the Feature
This example shows an application-style use of the feature, with its surrounding setup visible.
<?php
$cachingIterator = new CachingIterator(new ArrayIterator([10, 20, 30, 40]), CachingIterator::FULL_CACHE);
foreach ($cachingIterator as $item) {}
print_r($cachingIterator->getCache());
Output:
Array
(
[0] => 10
[1] => 20
[2] => 30
[3] => 40
)
The code is shown for learning. Adjust the class names, inputs and error handling to suit your application.
Important Behavior and Edge Cases
- The cache is populated during traversal and is not automatically complete at construction.
- Returns the entries retained by CachingIterator when FULL_CACHE is enabled.
- Observe differences in empty inputs, invalid states and optional extension availability where relevant.
Comparison With Related Approaches
| Approach | Important Difference |
|---|---|
CachingIterator::getCache | Returns the entries retained by CachingIterator when FULL_CACHE is enabled. |
| ArrayIterator | ArrayIterator does not retain a separate cache of visited entries; CachingIterator can cache them when configured. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
Ignoring the documented state or precondition of CachingIterator::getCache | The cache is populated during traversal and is not automatically complete at construction. |
| Expecting a different type of result | Read the declared return type and distinguish returned values from changes to the source object. |
| Assuming a related API works identically | ArrayIterator does not retain a separate cache of visited entries; CachingIterator can cache them when configured. |
Key Takeaways
- Returns the entries retained by CachingIterator when FULL_CACHE is enabled.
- The cache is populated during traversal and is not automatically complete at construction.
- Use the example that matches the values, runtime version and dependencies in your application.
CachingIterator::getCache is useful when its behavior matches the data structure and lifecycle of your PHP application. Choose it with a clear understanding of its preconditions and returned values.