What is the good example of using 'func_get_arg' in PHP?

Question

I just have found out that there is a function called func_get_arg in PHP which enables developer to use variant style of getting arguments. It seems to be very useful because number of argument can now be arbitrary, but I cannot think of any good example of using it.

What are the some examples of using this function to fully benefit its polymorphic characteristic?

Answer 1

I usually use func_get_args() which is easier to use if wanting multiple arguments.

For example, to recreate PHP's max().

function max() {    $max = -PHP_INT_MAX;    foreach(func_get_args() as $arg) {       if ($arg > $max) {           $max = $arg;       }    }    return $max; } 

CodePad.

Now you can do echo max(1,5,7,3) and get 7.

Answer 2

First of all, you are using the term "polymorphism" totally wrong. Polymorphism is a concept in object-oriented programming, and it has nothing to do with variable number of arguments in functions.

In my experience, all func_get_args allows you to do is add a little syntactic sugar.

Think of a function that can take any number of integers and return their sum. (I 'm cheating, as this already exists in array_sum. But cheating is good if it keeps the example simple). You could do it this way:

// you can leave "array" out; I have it because we should be getting one here function sum1(array $integers) {     return array_sum($integers); } 

Now you would call this like so:

$sum = sum1(array(1)); $sum = sum1(array(1, 2, 3, 4)); 

This isn't very pretty. But we can do better:

function sum2() {     $integers = func_get_args();     return array_sum($integers); } 

Now you can call it like this:

$sum = sum2(1); $sum = sum2(1, 2, 3, 4);