PHP enum_exists() Function: Usage and Examples

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

Detects whether a native enum is defined, with optional autoload.

What Is enum_exists in PHP?

Detects whether a native enum is defined, with optional autoload.

Syntax:

enum_exists(string $enum, bool $autoload = ...): bool

The method accepts the following parameters:

• $enum — Required. A string parameter named enum; the examples below show a supported value.
• $autoload — Optional. A bool parameter named autoload; the examples below show a supported value.

Return type declared by PHP: bool. 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

enum WorkflowState: string { case Draft = "draft"; case Live = "live"; }
var_dump(enum_exists(WorkflowState::class));

Output:

bool(true)

Detects whether a native enum is defined, with optional autoload.

Example 2: A Different Input

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

<?php

enum WorkflowState: string { case Draft = "draft"; case Live = "live"; }
var_dump(enum_exists(WorkflowState::class));
// The output reflects definitions in this PHP process.

Output:

bool(true)

Classes are not enums even when they contain enum-like constants.

Practical Example: Applying the Feature

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

<?php

enum WorkflowState: string { case Draft = "draft"; case Live = "live"; }
var_dump(enum_exists(WorkflowState::class));
// Use this result while deciding how to handle optional application features.

Output:

bool(true)

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

Important Behavior and Edge Cases

• Classes are not enums even when they contain enum-like constants.
• Detects whether a native enum is defined, with optional autoload.
• Observe differences in empty inputs, invalid states and optional extension availability where relevant.

Comparison With Related Approaches

Common Beginner Mistakes

Key Takeaways

• Detects whether a native enum is defined, with optional autoload.
• Classes are not enums even when they contain enum-like constants.
• Use the example that matches the values, runtime version and dependencies in your application.

enum_exists 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.