PHP ReflectionIntersectionType::getTypes() Method: Usage and Examples

When building tools that inspect PHP code, ReflectionIntersectionType::getTypes() helps answer a focused question: returns the individual class/interface ReflectionNamedType parts of an intersection type.

Reflection is useful in framework tooling, dependency injection, testing, code inspection and debugging.

What Is ReflectionIntersectionType::getTypes()?

Returns the individual class/interface ReflectionNamedType parts of an intersection type.

Its method signature is:

public function getTypes(): array

This method has no required arguments.

Return value: array

Example 1: Inspect the basic behavior

Start with a self-contained PHP declaration and inspect the method result.

<?php

declare(strict_types=1);

function receiveItems(Iterator&Countable $items): void {}
$parameterReflection = (new ReflectionFunction('receiveItems'))->getParameters()[0];
$intersection = $parameterReflection->getType();

$result = $intersection->getTypes();
echo implode(" & ", array_map(static fn($type) => $type->getName(), $result));

Output:

Iterator & Countable

Explanation: Returns the individual class/interface ReflectionNamedType parts of an intersection type.

Example 2: Compare a second case

Next, change the reflected declaration or parameter to observe a related situation.

<?php

declare(strict_types=1);

function receiveItems(Iterator&Countable $items): void {}
$parameterReflection = (new ReflectionFunction('receiveItems'))->getParameters()[0];
$intersection = $parameterReflection->getType();

$result = $intersection->getTypes();
echo implode(" & ", array_map(static fn($type) => $type->getName(), $result));

// Check the returned value type before using the result.
echo "\nResult type: " . get_debug_type($result);

Output:

Iterator & Countable
Result type: array

Explanation: Every value must satisfy every intersected type; union types mean something different.

Practical Example: Apply the operation in context

This final case shows how the same API can be used when inspecting application definitions.

<?php

declare(strict_types=1);

function receiveItems(Iterator&Countable $items): void {}
$parameterReflection = (new ReflectionFunction('receiveItems'))->getParameters()[0];
$intersection = $parameterReflection->getType();

$result = $intersection->getTypes();
echo implode(" & ", array_map(static fn($type) => $type->getName(), $result));

// Use the reflection result in a simple decision.
if (is_bool($result)) {
    echo "\nStatus: " . ($result ? "yes" : "no");
} elseif (is_array($result)) {
    echo "\nEntries: " . count($result);
} elseif ($result === null) {
    echo "\nNo value returned";
} else {
    echo "\nReflection result available";
}

Output:

Iterator & Countable
Entries: 2

Explanation: ReflectionUnionType::getTypes returns alternatives instead.

Important Behavior and Edge Cases

• Every value must satisfy every intersected type; union types mean something different.
• ReflectionUnionType::getTypes returns alternatives instead.
• Reflection describes declarations and runtime state; requesting metadata does not automatically validate or sanitize application input.

Comparison With Related Approaches

Common Beginner Mistakes

Key Takeaways

• Returns the individual class/interface ReflectionNamedType parts of an intersection type.
• Every value must satisfy every intersected type; union types mean something different.
• ReflectionUnionType::getTypes returns alternatives instead.

Use ReflectionIntersectionType::getTypes() when you need the precise metadata or behavior demonstrated above. Keep the target declaration and relevant PHP version in mind when adapting the examples.