spl_object_hash returns a string identifier for an object within the current runtime.
The examples explain the data format, expected results and the difference between this API and nearby cryptographic operations.
What It Does
The operation is intended for: spl_object_hash returns a string identifier for an object within the current runtime.
Part of core PHP or a normally bundled standard extension; check your deployment configuration.
Syntax and Return Value
spl_object_hash(object $object): string| Parameter | Purpose |
|---|---|
| $object (object) | Use the PHP signature above to determine the exact expected input type; validate untrusted inputs before calling. |
The declared return type is shown above. Errors can include false results or exceptions depending on this API: Object hashes are not persistent IDs, security tokens or guaranteed globally unique values; values may be reused after destruction.
Example 1: Basic Operation
A runtime-only identifier may be reused; it is not suitable for a database primary key.
<?php
$entity = new stdClass();
$hash = spl_object_hash($entity);
echo strlen($hash);Example 2: A Different Use Case
Compare distinct and repeated object references to see the scope of runtime identity.
<?php
// Check the alternative case.
$first = new stdClass();
$second = new stdClass();
var_dump(spl_object_hash($first) !== spl_object_hash($second));Practical Example: Checking the Result
Compare distinct and repeated object references to see the scope of runtime identity.
<?php
// Verify the expected behavior before using results.
$object = new stdClass();
var_dump(spl_object_hash($object) === spl_object_hash($object));Important Behavior and Edge Cases
Object hashes are not persistent IDs, security tokens or guaranteed globally unique values; values may be reused after destruction.
Object hashes are not persistent IDs, security tokens or guaranteed globally unique values; values may be reused after destruction.
Comparison with Related Functions
| Approach | Key distinction |
|---|---|
| spl_object_hash | spl_object_hash returns a string identifier for an object within the current runtime. |
| Related technique | spl_object_id returns an integer runtime identifier; WeakMap is often preferable for transient object metadata. |
Common Beginner Mistakes
| Mistake | Correct approach |
|---|---|
| Confusing this operation with a neighboring cryptographic or security mechanism | spl_object_id returns an integer runtime identifier; WeakMap is often preferable for transient object metadata. |
| Ignoring a security prerequisite or failure case | Object hashes are not persistent IDs, security tokens or guaranteed globally unique values; values may be reused after destruction. |
Key Takeaways
- spl_object_hash returns a string identifier for an object within the current runtime.
- Object hashes are not persistent IDs, security tokens or guaranteed globally unique values; values may be reused after destruction.
- spl_object_id returns an integer runtime identifier; WeakMap is often preferable for transient object metadata.
Apply this behavior to a real application only after confirming the required extension, configuration and failure handling on the deployment runtime.