What are the breakthroughs in the new features of PHP functions compared with previous versions?

New features of PHP functions include: Type declaration: used to declare parameter and return value types to improve code readability and type safety. Properties: You can store function-related data, avoid using global variables, and make the code more modular. Initializer: Allows default values ​​to be set during function definition, simplifying function definition. Coalescing operator (null merging operator): Returns the first non-null value, or returns the default value when all values ​​are null, which is convenient for handling scenarios where null values ​​can be used.

New features of PHP functions: innovations from previous versions

PHP functions are the core of the programming language. With the iteration of versions Continuously develop and improve. Since the release of PHP 8.0, many breakthroughs have been made in function functions, including type declarations, properties, initializers, merging operators (null merging operators), etc.

Type declarations

PHP 8.0 introduces type declarations for function parameters and return values. This not only improves code readability, but also enhances type safety and helps catch errors early.

Syntax:

function myFunction(int $param1, string $param2) : array
{
    // ...
}

Attributes

Function attributes can store data related to the function and can be accessed both inside and outside the function. This avoids the use of global variables and makes the code more modular.

Syntax:

class MyClass
{
    public static function myFunction() : void
    {
        self::$prop = 'value';
    }
}

Initializer

Function initializer allows setting default values ​​when the function is defined. This simplifies function definition without requiring additional checks or assignments in the function body.

Syntax:

function myFunction(string $param = 'default')
{
    // ...
}

Combining operator (null merging operator)

This operator (??) returns the first non-null value, Or return the default value if all values ​​are null. This is very convenient when dealing with nullable scenarios.

Syntax:

$result = $value1 ?? $value2 ?? 'default';

Practical case

Consider a PHP function that obtains the user's name and returns a welcome message:

function greetUser(string $name = null) : string
{
    // 验证输入
    if (empty($name)) {
        throw new InvalidArgumentException('Name cannot be empty');
    }

    // 返回欢迎消息
    return "Welcome $name!";
}

In this example, we use a type declaration to ensure that $name is a string. We also use the null merging operator to set a default exception message.

Conclusion

New features of PHP functions greatly enhance code quality, readability, and security. They allow developers to write cleaner, more robust code. By understanding these features, developers can take full advantage of PHP's power and create more efficient and reliable applications.

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