Today I learned

[sneakyimp]

dalecosp and Rampling, for all her modern foibles, was something to behold.

[sneakyimp]

TIL that returning false works if you declare return type int:

function foo() : int {
        return false;
}
var_dump(foo());

the result:

int(0)

but returning NULL from an int function throws an exception:

function foo() : int {
        return null;
}
var_dump(foo());

the result:

PHP Fatal error:  Uncaught TypeError: Return value of foo() must be of the type integer, null returned in /tmp/a.php:3
Stack trace:
#0 /tmp/a.php(5): foo()
#1 {main}
  thrown in /tmp/a.php on line 3

[Weedpacket]

sneakyimp

You'll also get that if you try to return a non-numeric string (a numeric string would be recast).

Also, attempting to return anything other than an int fail if you declare(strict_types=1);.

Returning null is hazardous, and equivalent to returning nothing at all (return null; is identical in meaning to return;; if a function is supposed to return a value, return; looks wrong). If for some reason you do want nulls hanging around, you can declare the possibility as function foo(): ?int.

[cluelessPHP]

Today I learned Mira Furlan is dead, this year sucks let's go to 2022

[sneakyimp]

TIL that the U.S. Government website for reporting online crime does not work:

 curl -v https://www.ic3.gov/complaint/default.aspx
*   Trying 65.201.175.169:443...
* TCP_NODELAY set
*   Trying 2600:803:c20::3:16:443...
* TCP_NODELAY set
* Immediate connect fail for 2600:803:c20::3:16: Network is unreachable
*   Trying 2600:803:c20::3:15:443...
* TCP_NODELAY set
* Immediate connect fail for 2600:803:c20::3:15: Network is unreachable
*   Trying 2600:803:c20::3:16:443...
* TCP_NODELAY set
* Immediate connect fail for 2600:803:c20::3:16: Network is unreachable
*   Trying 2600:803:c20::3:15:443...
* TCP_NODELAY set
* Immediate connect fail for 2600:803:c20::3:15: Network is unreachable

[jjgupta915]

Today I learned PHP filters. I really enjoy the PHP language while I am learning it.

[NogDog]

TIL (thanks to sneakyimp) that you can do...

16:16 $ /usr/bin/php -a
Interactive shell

php > $😊 = 'happy';
php > echo $😊;
happy
php >

[sneakyimp]

you can define emoji classes and namespaces, too:

class 😊 {
  public static function ☹️(){
    echo "🎭\n";
  }
}
😊::☹️();

[NogDog]

sneakyimp -- There can be a new variant of PHP "code golf" now. 🙂

[Weedpacket]

sneakyimp

TIL (not really today, but it came up again today) that a nonbreaking space is a valid character that can be used in identifiers.

<?php
$fo = 42;
$fo = 17;
echo $fo ;

Outputs 42 because of course that's $fo  in the first and third positions, but only $fo in the middle.

And it's also valid in constants as well (strictly speaking, almost all strings are valid as constant names, but most of them can't be used without wrapping them in constant()):

<?php
define(' ', 42);
function foo() { return ;}
echo foo();

Edit: Hey; still got the error message but the thread got bumped to the top of the list!

[SamanthaRoss]

Today i learned how to register here! 😃

[cluelessPHP]

Today I learned how to turn my old laptop into a server at home

[sneakyimp]

cluelessPHP linux?

[cluelessPHP]

sneakyimp Running it on windows machine

Today I learned to set up virtual machines and pint to different projects

[Weedpacket]

Okay, so array_map(null, $array1, $array2, $array, ...) can be used to zip several arrays together. array_map(null, [1,2,3], [4,5,6]) == [[1,4], [2,5], [3,6]]. And then you've got the destructuring operator "..." and now you can have a general array-transpose operation:

$array = [[1,2,3], [4,5,6], [7,8,9]];
array_map(null, ...$array) == [[1,4,7], [2,5,8], [3,6,9]];

Which is all well, and good. But TIL:

array_map(null, ...[[a,b,c], [d,e,f], [g,h,i], [j,k,l]]) == [[a,d,g,j], [b,e,h,k], [c,f,i,l]]
array_map(null, ...[[a,b,c], [d,e,f], [g,h,i]]) == [[a,d,g], [b,e,h], [c,f,i]]
array_map(null, ...[[a,b,c], [d,e,f]]) == [[a,d], [b,e], [c,f]]
array_map(null, ...[[a,b,c]]) == [a, b, c]

4 arrays of 3 elements each becomes 3 arrays of 4 elements each
3 arrays of 3 elements each becomes 3 arrays of 3 elements each
2 arrays of 3 elements each becomes 3 arrays of 2 elements each
1 array  of 3 elements each becomes 1 array  of 3 elements each
One of these things is not like the others. And apparently it's not a bug. array_map(null, ...[[a,b,c]]) is equivalent to array_map(null, [a,b,c]) as it should be, but it was decided that the latter should be a no-op and just return its second argument unchanged.

[NogDog]

Weedpacket

if(!is_array($new_array[0])) {
    $new_array = [$new_array];
}

🙃

(It's been years since I touched array_map() -- thankfully? -- and have never run into that syntax, and kind of hope I never have a reason to use it. 😉 )

[Weedpacket]

NogDog
You don't like functional programming?

[NogDog]

Weedpacket You don't like functional programming?

Not a question of like/dislike, but more that I've not pursued it, other than reading/viewing a few high-level discussions at mainly theoretical levels -- no practical experience (intentionally) implementing it.

[Weedpacket]

NogDog Ah; your mention of "hope" made me think you had something against it.

For fun and the record, here's the method where I hit the snag, with the workaround included, just to give an idea of what things would start to look like without the array_map.

public function ConjunctionVisit(Conjunction $expr)
{
	// Look for substitutions to Conjunction-bound variables. If this happens (it shouldn't, but at present
	// there's nothing to stop it), we first replace the Conjunction's colliding bound variables with
	// newly-minted ones, then update its expression to use the newly-minted variables in place of
	// the existing ones. Then we can apply the substitutions we were actually passed.
	$new_substitutions = [];
	foreach($this->substitutions as [$var,])
	{
		if(in_array($var, $expr->variables, true))
		{
			$new_substitutions[] = [$var, LVariable()];
		}
	}
	if(empty($new_substitutions))
	{
		// No substitutions of bound variables. Business as usual, then.
		$expression = $expr->expression->accept($this);
		return ($expression === $expr->expression) ? $expr : Conjunction($expression, $expr->variables);
	}

// If the number of new substitutions is 1 then array_map(null, ...) breaks down
// (this is known but undocumented behaviour: array_map(null, array) is a no-op)
if(count($new_substitutions) == 1)
{
	$existing_variables = [$new_substitutions[0][0]];
	$new_variables = [$new_substitutions[0][1]];
}
else
{
	[$existing_variables, $new_variables] = array_map(null, ...$new_substitutions);
}
$new_variables = array_map(function($var)use($existing_variables, $new_variables)
{
	$i = array_search($var, $existing_variables, true);
	return ($i !== false) ? $new_variables[$i] : $var;
}, $expr->variables);
return Conjunction($expr->expression->accept(Substituting(...$new_substitutions, ...$this->substitutions)), $new_variables);
}

[NogDog]

Weedpacket your mention of "hope" made me think you had something against it

Nah, more that I had recollections of trying to use array_map() for something way back when and finding it less than easy to comprehend at the time, and that this twist on it looked like it might cause a similar mind-ache. 🙂 (Hopefully I'm a bit better programmer now and maybe it would come more easily, but the situation has not arisen since then where I ended up on the manual page for array_map().)

[NogDog]

TIL: you can flip an image horizontally just via CSS:

<img src='/smurf.gif' height="150px" style="transform: scaleX(-1);">

PS: Yes, I'm using a "Smurf" image for an internal tool on a project which ended up with the acronym "SMRF". 🙂

[Weedpacket]

NogDog You could substitute an image of Papa Smurf over the Christmas season.