The PHP get_declared_traits API performs a focused operation on an object or value. The examples below show its effect on actual data.
Lists traits currently declared in PHP.
What Is get_declared_traits in PHP?
Lists traits currently declared in PHP.
Syntax:
get_declared_traits(): arrayThis operation has no parameters.
Return type declared by PHP: array. 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
trait AuditableTrait { public function audit(): string { return "logged"; } }
print_r(get_declared_traits());Output:
Array
(
[0] => AuditableTrait
)Lists traits currently declared in PHP.
Example 2: A Different Input
A different set of values shows the same operation in another situation.
<?php
trait AuditableTrait { public function audit(): string { return "logged"; } }
print_r(get_declared_traits());
// The output reflects definitions in this PHP process.Output:
Array
(
[0] => AuditableTrait
)Declared traits cannot be constructed directly as ordinary objects.
Practical Example: Applying the Feature
This example shows an application-style use of the feature, with its surrounding setup visible.
<?php
trait AuditableTrait { public function audit(): string { return "logged"; } }
print_r(get_declared_traits());
// Use this result while deciding how to handle optional application features.Output:
Array
(
[0] => AuditableTrait
)The code is shown for learning. Adjust the class names, inputs and error handling to suit your application.
Important Behavior and Edge Cases
- Declared traits cannot be constructed directly as ordinary objects.
- Lists traits currently declared in PHP.
- Observe differences in empty inputs, invalid states and optional extension availability where relevant.
Comparison With Related Approaches
| Approach | Important Difference |
|---|---|
get_declared_traits | Lists traits currently declared in PHP. |
| trait_exists() | get_declared_traits() lists declared traits; trait_exists() checks one candidate. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
Ignoring the documented state or precondition of get_declared_traits | Declared traits cannot be constructed directly as ordinary objects. |
| 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 | get_declared_traits() lists declared traits; trait_exists() checks one candidate. |
Key Takeaways
- Lists traits currently declared in PHP.
- Declared traits cannot be constructed directly as ordinary objects.
- Use the example that matches the values, runtime version and dependencies in your application.
get_declared_traits 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.