Can we alias a function in php?

问题:

is it possible to alias a function with a different name in PHP? if yes how ?

suppose we have this function sleep();

is there any quick way to make an alias called wait();

without writing this code

function wait ($seconds)  {
    sleep($seconds);
}

回答1:

PHP 5.6+ only

Starting with PHP 5.6 it is possible to alias a function by importing it:

use function sleep as wait;

回答2:

Until PHP 5.5

yup, function wait ($seconds) { sleep($seconds); } is the way to go. But if you are worried about having to change wait() should you change the number of parameters for sleep() then you might want to do the following instead:

function wait() { 
  return call_user_func_array("sleep", func_get_args());
}

回答3:

Nope, but you can do this:

$wait = 'sleep';
$wait($seconds);

This way you also resolve arguments-number-issues

回答4:

You can look at lambdas also if you have PHP 5.3

$wait = function($v) { return sleep($v); };

回答5:

If you aren't concerned with using PHP's "eval" instruction (which a lot of folks have a real problem with, but I do not), then you can use something like this:

function func_alias($target, $original) {
    eval("function $target() { \$args = func_get_args(); return call_user_func_array('$original', \$args); }");
}

I used it in some simple tests, and it seemed to work fairly well. Here is an example:

function hello($recipient) {
    echo "Hello, $recipient\n";
}

function helloMars() {
    hello('Mars');
}

func_alias('greeting', 'hello');
func_alias('greetingMars', 'helloMars');

greeting('World');
greetingMars();

回答6:

No, there's no quick way to do this in PHP. The language does not offer the ability to alias functions without writing a wrapper function.

If you really really really needed this, you could write a PHP extension that would do this for you. However, to use the extension you'd need to compile your extension and configure PHP to us this extension, which means the portability of your application would be greatly reduced.

回答7:

No, functions aren't 1st-class citizens so there's no wait = sleep like Javascript for example. You basically have to do what you put in your question:

function wait ($seconds) { sleep($seconds); }

回答8:

you can use runkit extension

http://us.php.net/manual/en/function.runkit-function-copy.php

回答9:

function alias($function)
{
    return function (/* *args */) use ($function){
        return call_user_func_array( $function, func_get_args() );
    };
}

$uppercase = alias('strtoupper');
$wait      = alias('sleep');

echo $uppercase('hello!'); // -> 'HELLO!'

$wait(1); // -> …

回答10:

If your PHP doesn't support use x as y syntax, in older PHP version you can define anonymous function:

$wait = create_function('$seconds', 'sleep($seconds);');
$wait(1);

Or place the code inside the constant, e.g.:

define('wait', 'sleep(1);');
eval(wait);

See also: What can I use instead of eval()?

This is especially useful if you've long piece of code, and you don't want to repeat it or the code is not useful for a new function either.

---

There is also function posted by Dave H which is very useful for creating an alias of a user function:

function create_function_alias($function_name, $alias_name) 
{ 
    if(function_exists($alias_name)) 
        return false; 
    $rf = new ReflectionFunction($function_name); 
    $fproto = $alias_name.'('; 
    $fcall = $function_name.'('; 
    $need_comma = false; 

    foreach($rf->getParameters() as $param) 
    { 
        if($need_comma) 
        { 
            $fproto .= ','; 
            $fcall .= ','; 
        } 

        $fproto .= '$'.$param->getName(); 
        $fcall .= '$'.$param->getName(); 

        if($param->isOptional() && $param->isDefaultValueAvailable()) 
        { 
            $val = $param->getDefaultValue(); 
            if(is_string($val)) 
                $val = "'$val'"; 
            $fproto .= ' = '.$val; 
        } 
        $need_comma = true; 
    } 
    $fproto .= ')'; 
    $fcall .= ')'; 

    $f = "function $fproto".PHP_EOL; 
    $f .= '{return '.$fcall.';}'; 

    eval($f); 
    return true; 
}

回答11:

nope. the way you wrote is the best way to do it.

回答12:

No, there's no quick way to do so - at least for anything before PHP v5.3, and it's not a particularly good idea to do so either. It simply complicates matters.

回答13:

Since PHP 5.6

This is especially helpful for use in classes with magic methods.

class User extends SomethingWithMagicMethods {

    public function Listings(...$args) {
        return $this->Children(...$args);
    }

}

But I'm pretty sure it works with regular functions too.

function UserListings(...$args) {
    return UserChildren(...$args);
}

Source: PHP: New features -> "Variadic functions via ..."

回答14:

I know this is old, but you can always

$wait = 'sleep';
$wait();

回答15:

What I have used in my CLASS

function __call($name, $args) {
    $alias['execute']=array('done','finish');
    $alias['query']=array('prepare','do');
    if (in_array($name,$alias['execute'])){
        call_user_func_array("execute",$args);
        return TRUE;
    }elseif(in_array($name,$alias['query'])){
        call_user_func_array("query",$args);
        return TRUE;
    }
    die($this->_errors.' Invalid method:'.$name.PHP_EOL);
}