How is the type of return value of a PHP function specified?

The type of function return value in PHP can be specified through type hints, including the following steps: Use a colon (:) after the function declaration. Specify the expected return type. PHP supports built-in types and custom types. Type hints improve code readability, maintainability, and testability.

#How is the type of the return value of a PHP function specified?

In PHP, you can specify a type for a function return value by specifying a type hint. Type hints help make your code more readable, maintainable, and testable.

Use type hints to specify return value types

Type hints are specified using a colon (:) followed by the desired return type:

function get_name(): string {
    return 'Alice';
}

Above example , get_name() function declaration returns a string.

Supported Types

PHP supports the following built-in types:

• array
• callable
• bool (boolean)
• double (float)
• float
• int (integer)
• string
• void

You can also use custom classes and interfaces as return types:

class Person {
    // ...
}

function create_person(): Person {
    // ...
}

Practical case

The following example shows a function using type hints, which calculates two The sum of numbers:

function calculate_sum(int $x, int $y): int {
    return $x + $y;
}

// 用法
$result = calculate_sum(5, 10); // 结果：15

Note:

• Type hints are optional, and functions that do not specify type hints return mixed type.
• PHP 7.0 and higher supports type hints.
• If the return value of the function does not match the declared type, a TypeError will be triggered.

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