Php parameter type or null
Nullable types Type declarations for parameters and return values can now be marked as nullable by prefixing the type name with a question mark. This signifies that as well as the specified type, Show
testReturn(): ?string The above example will output: string(10) "elePHPant" NULL string(10) "elePHPant" NULL Uncaught Error: Too few arguments to function test(), 0 passed in... Void functions A void return type has been introduced. Functions declared with void as their return type must either omit their return statement altogether, or use an empty return statement.
The above example will output: Attempting to use a void function's return value
simply evaluates to Symmetric array destructuring The shorthand array syntax (
Class constant visibilitySupport for specifying the visibility of class constants has been added.
iterable pseudo-typeA new pseudo-type (similar to callable) called iterable has been introduced. It may be used in parameter and return types, where it accepts either arrays or objects that implement the Traversable interface. With respect to subtyping, parameter types of child classes may broaden a parent's declaration of array or Traversable to iterable. With return types, child classes may narrow a parent's return type of iterable to array or an object that implements Traversable.
Multi catch exception handling Multiple exceptions per catch block may
now be specified using the pipe character (
Support for keys in list() You can now specify keys in
list(), or its new shorthand
Support for negative string offsets Support for negative string offsets has been added to the
string manipulation functions accepting offsets, as well as to string indexing with
The above example will output: Negative string and array offsets are now also supported in the simple variable parsing syntax inside of strings.
The above example will output: The last character of 'bar' is 'r'. Support for AEAD in ext/opensslSupport for AEAD (modes GCM and CCM) have been added by extending the openssl_encrypt() and openssl_decrypt() functions with additional parameters. Convert callables to Closures with Closure::fromCallable()A new static method has been introduced to the Closure class to allow for callables to be easily converted into Closure objects.
privateFunction($param) The above example will output: Asynchronous signal handlingA new function called pcntl_async_signals() has been introduced to enable asynchronous signal handling without using ticks (which introduce a lot of overhead).
The above example will output: HTTP/2 server push support in ext/curl Support for server push has been added to the CURL extension (requires version 7.46 and above). This can be leveraged through the curl_multi_setopt() function with the new Stream Context OptionsThe tcp_nodelay stream context option has been added. DYM ¶ 4 years ago
unti1x ¶ 4 years ago
Is null a type in PHP?PHP NULL Value
Null is a special data type which can have only one value: NULL. A variable of data type NULL is a variable that has no value assigned to it.
Should I use type hinting in PHP?Apparently 'type hinting' in PHP can be defined as follows: "Type hinting" forces you to only pass objects of a particular type. This prevents you from passing incompatible values, and creates a standard if you're working with a team etc.
What are PHP parameters?PHP Parameterized functions
They are declared inside the brackets, after the function name. A parameter is a value you pass to a function or strategy. It can be a few value put away in a variable, or a literal value you pass on the fly. They are moreover known as arguments.
Are parameters optional in PHP?When creating functions in PHP it is possible to provide default parameters so that when a parameter is not passed to the function it is still available within the function with a pre-defined value. These default values can also be called optional parameters because they don't need to be passed to the function.
|