PHP handles type prompts and return types by allowing developers to explicitly declare the expected data types of function parameters and return values. Specific methods include: 1. Type prompt is used to ensure that the function or method receives the correct type of parameters, otherwise TypeError is raised; 2. Return the type declaration specifies the value type that the function should return, prevent errors and clarify expectations; 3. Supported types include scalar types (string, int, float, bool), arrays, callable types, class names, union types (PHP 8.0) and intersection types (PHP 8.1); 4. If you return a value that may be null, you need to use a nullable type such as?string; 5. Enable declare(strict_types=1) to force strict type checking and disable automatic type conversion. Together, these features improve code readability and maintainability, and help detect errors early.

PHP handles type hinging and return types by allowing developers to explicitly declare the expected data types for function parameters and return values. This helps catch bugs early, improves code readability, and makes the codebase more maintained.

Type Hinting in PHP

Type hinging ensures that a function or method receives arguments of the correct type. If the wrong type is passed, PHP throws a TypeError .

Basic Usage:

 function saysHello(string $name): void {
    echo "Hello, $name";
}

In this example:

• The function expects a string for $name .
• Passing an integer or object will result in an error.

Supported Types for Hinting:

• string , int , float , bool
• array , callable
• Class names (eg, User )
• Union types ( Type1|Type2 ) — available from PHP 8.0
• Intersection types ( Type1&Type2 ) — available from PHP 8.1

One common mistake is forgetting that scalar types like int or string are enforced strictly. For example, passing "123" where int is expected will cause an error instead of being coerced automatically unless you handle it manually.

Return Type Declarations

Return type declarations specify what type of value a function should return. Like type hints, they help prevent bugs and make expectations clear.

Example:

 function getAge(): int {
    return "thirty"; // This will throw a TypeError
}

Available Return Types:

• All scalar types ( int , float , string , bool )
• Compound types ( array , callable )
• Object types ( User , DateTime , etc.)
• void – used when no return value is expected
• never – indicates that the function doesn't return at all (eg, throws exception or exits)

A small but important detail: if you're returning a value that might be null , you need to use a nullable type like ?string . Otherwise, returning null where a string is expected will trigger an error.

Combining Type Hints and Return Types

Using both together leads to clearer, safer functions:

 function add(int $a, int $b): int {
    return $a $b;
}

This tells anyone reading the code:

• Only integers should be passed
• The function always returns an integer

It also helps IDEs give better auto-completion and refactoring suggestions.

Some practical benefits:

• Easier debugging due to clearer errors
• Better documentation embedded in the code
• Improved collaboration across teams

Enabling Strict Mode

By default, PHP tries to coerce values into the expected type (eg, converting "123" to 123 for an int ). But you can enforce strict checks using:

 declare(strict_types=1);

With strict mode enabled:

• Type mismatches cause TypeError exceptions
• No automatic type conversion happens

Note: strict_types only affects the file it's declared in. It's best to enable it at the top of each PHP file to ensure consistent behavior.

Basically that's it.

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