PHP 7 typed and difference between argument numbers and parameters

Question

Reading in:

https://secure.php.net/manual/en/mi

found out the following example:

function arraysSum(array ...$arrays): array
{
    return array_map(function(array $array): int {
        return array_sum($array);
    }, $arrays);
}

print_r(arraysSum([1,2,3], [4,5,6], [7,8,9]));

But understand that arraysSum in its definition has only 1 argument;

arraysSum(array ...$arrays)

But on the call are passed 3 arguments

arraysSum([1,2,3], [4,5,6], [7,8,9])

My question is this::

Let’s say I need to define a second argument for this function as below.

function arraysSum(array ...$arrays, int numero): array
{
    return array_map(function(array $array): int {
        return array_sum($array);
    }, $arrays);
}

$numero = 125;
print_r(arraysSum([1,2,3], [4,5,6], [7,8,9]), $numero);

This will generate an error.

What to do to use typed language in these cases knowing that all parameters passed in the function will be summed?

There seems to be a contradiction between the number of function parameters and the number of arguments passed in the call.

I don’t quite understand it!

My goal is to do something like:

<?php

function teste( string... $_array, string a ) : array {

    return array_push($_array, a);

}

print_r( teste (...["teste","2"], "adicionado") );

but without the 3 points in the ...["teste", "2"].

Is there any way?

That’s the mistake you’re making:

Parse error: syntax error, unexpected 'a' (T_STRING), expecting variable (T_VARIABLE) in /var/www/html/gasmuriae.com.br/web/gceu/teste.php on line 10

Answer 1

What you need is not Operator spread, the ..., then there is no way to use it to do what you wish.

The Operator spread groups all parameters passed to function within one array. If you use it in the first parameter, it means that all will belong to the array, so setting a second parameter will give error. You may have other parameters before, but not after. Read more in the official documentation Variable number of arguments.

What you need is only two parameters, one of which is array:

function my_push(array $arr, string $value): array {
    array_push($arr, $value);
    return $arr;
}

print_r(my_push(["teste","2"], "adicionado"));

Staying:

Array
(
    [0] => teste
    [1] => 2
    [2] => adicionado
)

---

Solution "Kids don’t do that at home"

You have a saw and a hammer, and you need to fix a nail. This solution shows you how to use the saw _(ツ)_/

By reversing the positions of the parameters you can get something similar to what you want, but it is wrong to use the operator spread.

function my_push(string $value, string ...$arr): array {
    array_push($arr, $value);
    return $arr;
}

print_r(my_push('adicionado', ...[1, 2]));

Resulting:

Array
(
    [0] => 1
    [1] => 2
    [2] => adicionado
)

But using the operator spread, will also allow to make my_push(1, 2, 3), producing the same result. Read only this function call and tell me who is being added to whom? Bad for maintenance, don’t do that. It will only be a matter of time to repent - if you work as a team, that time will decrease significantly.

Realize that even putting the type string in the parameter PHP accepted I pass a list of integers. It’s PHP, it does it. It lets you pass a list of integers, but will do the casting for string. You pass a list of integers and receive a list of strings - another thing that only complicates the life of those who are reading the code.