[SOLVED] Removing an element from an array without leaving a hole in the index sequence

[Errant_Shadow]

As my title suggests, I'm removing an element in an array, but what's happening is that it's leaving a hole in the index sequence.

 

I start with something like...

$myArray = array("dog", "fish", "cat");

 

then I remove index number 1 ("fish") with unset...

unset($myArray[1]);

 

but it leaves the keys in tact, returning

.[0] => "dog"

.[2] => "cat"

 

what I need it to do is return:

.[0] => "dog"

.[1] => "cat"

 

because if I were to, say, use a for() loop to increment through the array, it would return an error when it got to index 1, since it doesn't exist, and since the last index of the array is now 1 number higher than it should be, the for() loop won't even check it; it'll hit the end of the loop before the index variable is high enough.

 

I've read through a lot of array documentation in the PHP manual, but I've found nothing that's worked so far... any advice on this one?

 

 

[MadTechie]

<?php
$myArray = array("dog", "fish", "cat");
unset($myArray[1]);
$myArray =array_values($myArray);
?>

 

 

EDIT:

may i also suggest you look at foreach

 

ie

<?php
$myArray = array("dog", "fish", "cat");
unset($myArray[1]);
foreach($myArray as $A)
{
echo "$A<br>/n";
}
?>

 

[Errant_Shadow]

What I'm doing is setting a few multidimensional arrays from mysql and using the data in a browser game. So when the game calls for it, I need to remove certain elements, such as NPC competitors from those arrays as I process them over and over.

 

... would it work to use next() last() and current() in lieu of a traditional for() loop?

 

something like...

 

<?php
// for a given array
$myArray = array(1, 2 ... "n");

// find the value of the last element in the array
$endof_myArray = end($myArray);

// then reset the pointer, checking to make sure the current index does not point to the end,
// and moving the pointer ahead by one for each successive loop...
for (reset($myArray); current($myArray) != $endof_myArray; next($myArray) {
// do some stuff...
if (current($myArray) != "foobar") {
	current($myArray) = "foobar"
} // end if ()
} // end for ()
?>

[Errant_Shadow]

Actually, array_values() worked perfectly. I looked at that in the manual, but I had already read through almost everything else and I just skimmed it; never clicked with me to try it

 

Thank you very much for you help, MadTechie, I really appreciate it.

[Errant_Shadow]

On one last note:

 

on my method using reset(), current(), and next(). It -will- work, -but- my initial method was flawed.

 

<?php
// here, $r represents the current index in $racerArray

// first, I set up an $endof... variable to use in my loop, and then reset the internal pointer
$endof_racerArray_this_damage = end($racerArray[$r]['damage']);
reset($racerArray[$r]['damage']);

// now, using my array as the first arguement of the for() loop,
// as long as the current pointer is not set to the end of the array (using our $endof... variable),
// I move the pointer to the next index for each successive loop...
for ($racerArray[$r]['damage']; current($racerArray[$r]['damage']) != $endof_racerArray_this_damage; next($racerArray[$r]['damage'])) {

// unlike array_walk(), you can easily and directly modify your array's values
// and even access external arrays and use other variables inside the loop

// but this is an important part...
// if at any time inside this loop you create some criteria that would disturb the loop,
// for instance, such as destroying the array with unset(), or otherwise create an invalid
// argument, you -must- break the loop manually, so be careful
if ($stuff == "happening") {

	break;

} // end if()

} // end for ( ... )

?>

[MadTechie]

Okay i'm not sure but are you trying to do something like this

 

<?php
$racerArray = array(
			array("Name" => "Errant", "damage" => 0, "cheat" => false),
			array("Name" => "Shadow", "damage" => 0, "cheat" => false),
			array("Name" => "MadTechie", "damage" => 0, "cheat" => true)
			);

$stillraceing = true;
ob_start();
while($stillraceing)
{
foreach($racerArray as $RacerKey => $Racer)
{
	$stillraceing = (count($racerArray) > 1); //race until last person
	if(!$stillraceing) break;
	//take damage
	$damage = (rand(1,10) * rand(1,10));
	$racerArray[$RacerKey]['damage'] = ((!$Racer['cheat']))?$Racer['damage'] + $damage:$Racer['damage'];
	echo $Racer['Name']." Take $damage damage, ".(100-$racerArray[$RacerKey]['damage'])." Remaining<br>\n";

	//remove them
	if($racerArray[$RacerKey]['damage'] >= 100)
	{
		echo $Racer['Name']." is out of the race<br>\n";
		unset($racerArray[$RacerKey]);
	}
	flush();
	ob_flush();
}
}
$winner = current($racerArray);
echo $winner['Name']." Wins";
?>

 

PS: i always win

 

EDIT: updated the damage message

[Errant_Shadow]

*nods* I think so. I'll research foreach() some time in this coming week and I suspect I'll implement it.

 

My usual programming methods are to find some convoluted, overly complicated way to do something, then find out there's an easier way and re-write my code to use that ><

 

On the plus side, once I find that easier method, I'm slow to forget it

 

What does flush() and ob_flush() do here?

[MadTechie]

flush and ob_flush()

basically dump all the last echos to apache to output to the browser,,

 

if you run the code, without them, then run it again with them, your notice that without them it delays for a second or 2 and them dumps everything to screen, while with them it dumps them part at a time..

 

hope that makes sense,

[Errant_Shadow]

That makes sense. Sounds like it's easier on the server for larger processes.

[MadTechie]

Think of it this way

<?php
echo "Hello ";
sleep(5);
echo "World";
?>

this will display

Hello World

in just over 5 seconds

<?php
on_start();
echo "Hello ";
ob_flush();
flush();
sleep(5);
echo "World";
?>

this will display

Hello

then display 5 seconds later display

World

the final result is still

Hello World

but the flush means you didn't have to wait for the script to end