Legal values ​​for PHP function parameter types

Legal values ​​of PHP function parameter types include: 1. Array, 2. Boolean, 3. Callable method, 4. Floating point number, 5. Integer, 6. Object, 7. Resource, 8. String. For example, myFunction(int $number, string $name) will accept int and string parameters. Type hints help improve code readability, maintainability, and security.

Legal values ​​of PHP function parameter types

Specifying types for function parameters in PHP is a good habit, it can help improve the readability of the code performance, maintainability and security. The following is a list of function parameter types and their legal values ​​in PHP:

Array: array

Boolean: bool

Call method: callable

##Floating point number: float

Integer: int

Object: object

Resource: resource

String: string

For example, the following function will accept

int and string type parameters:

function myFunction(int $number, string $name): void
{
    // ...
}

To use type hints, precede the parameter name with a colon (

:) and then specify the type. You can also use null to specify that the parameter can be null, and void to specify that the function does not return any value.

Practical case:

The following is an example of a function using type hints:

function calculateTax(float $amount, int $percentage): float
{
    return $amount * ($percentage / 100);
}

$tax = calculateTax(100.0, 10); // 10.0

The

calculateTax function defined above will Accepts a floating point number parameter amount and an integer parameter percentage, and returns a calculated floating point number.

Another example:

function createNewUser(string $username, string $password, bool $isAdmin = false): object
{
    // 创建一个新的用户对象
    $user = new User($username, $password, $isAdmin);

    return $user;
}

$user = createNewUser('john', 'secret'); // 对象形式的用户

The

createNewUser function above will accept three parameters: two string parameters username and password , and an optional Boolean parameter isAdmin. It will create a new User object and return it.

The above is the detailed content of Legal values ​​for PHP function parameter types. For more information, please follow other related articles on the PHP Chinese website!