remove item from array?

[Anon]

Hi folks
Can someone tell me how to remove an item from an array?
I will only know the index value.

Also there is a post headed 'array function' below if you can lend any assistance?

THanks

Nick

[Anon]

Well, as for removing an item from an array, just do

unset($array[index]);

and it will be gone. However, this will not reindex the array. As for the second question, I have no idea what your talking about so I'll leave that to someone else 🙂

Chris King

[frymaster]

okay, i assume you mean you have an array like this:

$foo[0] = "cat"
$foo[1] = "dog"
$foo[2] = "guppy"
$foo[3] = "paramecium"

and you want to "remove" $foo[2] so that your array looks like:

$foo[0] = "cat"
$foo[1] = "dog"
$foo[2] = "paramecium"

ie, it is "repacked". if that is so then what you really want is a vector, not an array... but php doesn't do vectors (to my knowledge at least).

this func takes the array you have and an array of all the indexes you want to remove (ie if you want to remove indexes 3, 9 and 21 from the array, then those three numbers would be stored in $array_of_indexes_to_remove). it returns a new packed array.

note: i just wrote this off the top of my head with zero testing so there's a good chance it just won't work... but the idea is the important thing here... 🙂

function vector_remove($the_vector, $array_of_indexes_to_remove)
{
....for($i=0;$i<count($the_vector);$i++)
....{
........for($j=0;$j<count($array_of_indexes_to_remove);$j++)
........{
............if($array_of_indexes_to_remove[$j] == $i)
............{
................$i++;
................break;
............}
........}
........$new_vector[] = $the_vector[$i];
....}
....return $new_vector;
}

-frymaster

[Anon]

I wrote a response to a similar post:

$breakfast[1]="sausages";
$breakfast[2]="eggs";
$breakfast[3]="bacon";
$breakfast[4]="heart_failure";

function delete_page($num) {
global $breakfast;
unset($breakfast[$num]);
// concatenate
$temp=array();
$c=1; // Starting index for breakfasts
foreach ($breakfast as $food) {
$temp[$c++]=$food;
}
$breakfast=$temp;
}

var_dump($breakfast);
delete_page(2);
var_dump($breakfast);

that removes an item, then makes the rest of the indeces contiguous.

[frymaster]

are you saying that if you use unset() that when you run foreach it will skip over the unset index? i would be tempted to regard that as a bug rather than a feature.

i don't think you need $c

[knickerlas]

Thanks guys, I've gotta do some other stuff for 24hrs or so (can't make a living doing this in denmark) then I'll get right on it.

Thanks again for your efforts!

Nick

[Anon]

It does look like you don't need $c, but if you left it out, the array would start at 0, instead of 1.

Dave

[knickerlas]

Hi Dave,
I just tested your function and it works great! Thanks for that. The only thing I don't fully understand is the use of $c
When you say $temp[$c++]=$food; it looks like on the first iteration through the foreach() loop that it's value will be '2'.
How does this work?
I'm not a fan of 'cut and paste' coding so would really appreciate an 'idiot' explanation as with a little modification it will serve really well within the class I'm building.

Cheers

Nick

[Anon]

Well, that code was really just suited to the array given, but the $c is there so the first index set is '1' and not '0' (as I found out when I wrote it). The array specified started at 1, and the code without the $c would make it start at the pre-defined index. Ideally, the code would find the first index of a set variable and start on that, but this isn't a general-purpose snippet.

good luck!

Dave

[Anon]

cool - i just spent 2 days messing about with bloody splice - which mostly worked except when removing the last element of the array...

praise be

keith

[Anon]

this what you wrote ain't working, as i made count($new_vector) it made nice 0, any suggestions why?