You can read more about attributes in PHP RFC: Attributes v2. As attributes are mapped to classes it ensures that attributes are correctly typed, which reduces the major source of bugs in reliance on docblocks at runtime. The complexity of checking for attribute existence is O(1) compared to doc-block parsing or performance of strstr. Semantically the attribute declaration should be read as instantiating a class with the attribute name and passing arguments to the constructor.Īttributes are better than doc-block comments and are introduced as a new language construct. You can also declare attributes in the same line: > It is possible to use the same attribute name more than one time on the same declaration. Note that each function, class, property or other declaration can have multiple attributes. You can use attributes and doc-comments combination by adding attributes before or after a doc-block comment. Much like doc-comments, attributes are added before the declaration they belong to. classes (including anonymous classes), interfaces, traits.functions (including closures and short closures).Before this major update, PHP supported only doc-comments, an unstructured form of metadata.Īttributes syntax is very simple, attributes which are also called annotations are specially formatted text enclosed with “>.” They can be applied to PHP 8.0 offers a structured, syntactic form of metadata for declaring classes, class properties/methods, functions, parameters, and constants which are called attributes. Read more about named parameters in PHP RFC: Named Arguments. The parameter name must be an identifier, it’s impossible to specify it dynamically: my_function($ParamName: $value) This syntax is correct: htmlspecialchars($string, double_encode: false) īut this one is incorrect: htmlspecialchars(double_encode: false, $string) Īnother thing to avoid is using variables as argument names. You can use named and positional arguments together, but do not pass positional arguments after named arguments. Named arguments make the code more readable as this makes the meaning of the argument self-documenting.īut it is important to remember some syntax rules when using named arguments. It is useful to use named arguments in class constructors, as constructors can have many arguments with default values. It is especially great when you use it in object initialization.Īs function-named arguments are order-independent, you can arbitrarily skip default values, which makes life easier. This new feature simplifies the coding process, as it allows you to skip function default values, to have a self-documenting code. Note that the order of arguments does not matter, so this syntax is correct too: array_fill(value: 50, num: 100, start_index: 0) Here are some examples: // Case of positional arguments:Īrray_fill(start_index: 0, num: 100, value: 50) PHP 8.0 makes it possible to pass function parameters by their names instead of their position. Type system and error handling improvements.Consistent type errors for internal functions.Let’s discover the new features introduced by this new major update. Others are welcome to learn about all the new features of PHP 8 and about the JIT compiler in particular. If you don’t want to go into the details, scroll down to see how to enable it on 10Web. With 10Web, you can easily update your PHP to the PHP 8.0 version. It came with many new amazing features and optimizations such as named arguments, union types, attributes, constructor property promotion, match expression, nullsafe operator, JIT compiler, improvements in the type system, error handling, and consistency. PHP 8.0 is a major update that was released on November 26, 2020.
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