PHP get_declared_interfaces() Function: Usage and Examples

The PHP get_declared_interfaces API performs a focused operation on an object or value. The examples below show its effect on actual data.

Lists interface names currently defined.

What Is get_declared_interfaces in PHP?

Lists interface names currently defined.

Syntax:

get_declared_interfaces(): array

This 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

$interfaceNames = get_declared_interfaces();
echo in_array(Iterator::class, $interfaceNames, true) ? "available" : "missing";

Output:

available

Lists interface names currently defined.

Example 2: A Different Input

A different set of values shows the same operation in another situation.

<?php

$interfaceNames = get_declared_interfaces();
echo in_array(Iterator::class, $interfaceNames, true) ? "available" : "missing";
// The output reflects definitions in this PHP process.

Output:

available

Interfaces from optional extensions might not appear.

Practical Example: Applying the Feature

This example shows an application-style use of the feature, with its surrounding setup visible.

<?php

$interfaceNames = get_declared_interfaces();
echo in_array(Iterator::class, $interfaceNames, true) ? "available" : "missing";
// Use this result while deciding how to handle optional application features.

Output:

available

The code is shown for learning. Adjust the class names, inputs and error handling to suit your application.

Important Behavior and Edge Cases

• Interfaces from optional extensions might not appear.
• Lists interface names currently defined.
• Observe differences in empty inputs, invalid states and optional extension availability where relevant.

Comparison With Related Approaches

Common Beginner Mistakes

Key Takeaways

• Lists interface names currently defined.
• Interfaces from optional extensions might not appear.
• Use the example that matches the values, runtime version and dependencies in your application.

get_declared_interfaces 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.