Unsetting array values in a foreach loop [duplicate] - php

Question

This question already has answers here:
How do you remove an array element in a foreach loop?
(6 answers)
Closed 6 years ago.
I have a foreach loop set up to go through my array, check for a certain link, and if it finds it removes that link from the array.
My code:
foreach($images as $image)
{
if($image == 'http://i27.tinypic.com/29yk345.gif' ||
$image == 'http://img3.abload.de/img/10nx2340fhco.gif' ||
$image == 'http://i42.tinypic.com/9pp2456x.gif')
{
unset($images[$image]);
}
}
But it doesn't remove the array entires. It's probably something to do with $images[$image], as that's not the key of the array entry, only the content? Is there a way to do this without incorporating a counter?
Thanks.
EDIT: Thanks guys, but now I have another problem where the array entries don't actually get deleted.
My new code:
foreach($images[1] as $key => $image)
{
if($image == 'http://i27.tinypic.com/29yk345.gif')
$image == 'http://img3.abload.de/img/10nx2340fhco.gif' ||
$image == 'http://i42.tinypic.com/9pp2456x.gif')
{
unset($images[$key]);
}
}
$images is actuallty a two-dimensional array now hence why I need $images[1]. I have checked and it successfully goes around the array elements, and some elements do actually have some of those URLs in that I wish to delete, but they're not getting deleted. This is my $images array:
Array
(
[0] => Array
(
[0] => useless
[1] => useless
[2] => useless
[3] => useless
[4] => useless
)
[1] => Array
(
[0] => http://i27.tinypic.com/29yk345.gif
[1] => http://img3.abload.de/img/10nx2340fhco.gif
[2] => http://img3.abload.de/img/10nx2340fhco.gif
[3] => http://i42.tinypic.com/9pp2456x.gif
)
)
Thanks!

Answer 1

foreach($images as $key => $image)
{
if(in_array($image, array(
'http://i27.tinypic.com/29ykt1f.gif',
'http://img3.abload.de/img/10nxjl0fhco.gif',
'http://i42.tinypic.com/9pp2tx.gif',
))
{
unset($images[$key]);
}
}

Answer 2

Try that:
foreach ($images[1] as $key => &$image) {
if (yourConditionGoesHere) {
unset($images[1][$key])
}
}
unset($image); // detach reference after loop
Normally, foreach operates on a copy of your array so any changes you make, are made to that copy and don't affect the actual array.
So you need to unset the values via $images[$key];
The reference on &$image prevents the loop from creating a copy of the array which would waste memory.

Answer 3

To answer the initial question (after your edit), you need to unset($images[1][$key]);
Now some more infos how PHP works:
You can safely unset elements of the array in foreach loop, and it doesn't matter if you have & or not for the array item. See this code:
$a=[1,2,3,4,5];
foreach($a as $key=>$val)
{
if ($key==3) unset($a[$key]);
}
print_r($a);
This prints:
Array
(
[0] => 1
[1] => 2
[2] => 3
[4] => 5
)
So as you can see, if you unset correct thing within the foreach loop, everything works fine.

Answer 4

You can use the index of the array element to remove it from the array, the next time you use the $list variable, you will see that the array is changed.
Try something like this
foreach($list as $itemIndex => &$item) {
if($item['status'] === false) {
unset($list[$itemIndex]);
}
}

Answer 5

$image is in your case the value of the item and not the key. Use the following syntax to get the key too:
foreach ($images as $key => $value) {
/* … */
}
Now you can delete the item with unset($images[$key]).

Answer 6

One solution would be to use the key of your items to remove them -- you can both the keys and the values, when looping using foreach.
For instance :
$arr = array(
'a' => 123,
'b' => 456,
'c' => 789,
);
foreach ($arr as $key => $item) {
if ($item == 456) {
unset($arr[$key]);
}
}
var_dump($arr);
Will give you this array, in the end :
array
'a' => int 123
'c' => int 789
Which means that, in your case, something like this should do the trick :
foreach($images as $key => $image)
{
if($image == 'http://i27.tinypic.com/29yk345.gif' ||
$image == 'http://img3.abload.de/img/10nx2340fhco.gif' ||
$image == 'http://i42.tinypic.com/9pp2456x.gif')
{
unset($images[$key]);
}
}

Answer 7

foreach($images as $key=>$image)
{
if($image == 'http://i27.tinypic.com/29ykt1f.gif' ||
$image == 'http://img3.abload.de/img/10nxjl0fhco.gif' ||
$image == 'http://i42.tinypic.com/9pp2tx.gif')
{ unset($images[$key]); }
}
!!foreach($images as $key=>$image
cause $image is the value, so $images[$image] make no sense.

Answer 8

You would also need a
$i--;
after each unset to not skip an element/
Because when you unset $item[45], the next element in the for-loop should be $item[45] - which was [46] before unsetting. If you would not do this, you'd always skip an element after unsetting.

Answer 9

Sorry for the late response, I recently had the same problem with PHP and found out that when working with arrays that do not use $key => $value structure, when using the foreach loop you actual copy the value of the position on the loop variable, in this case $image. Try using this code and it will fix your problem.
for ($i=0; $i < count($images[1]); $i++)
{
if($images[1][$i] == 'http://i27.tinypic.com/29yk345.gif' ||
$images[1][$i] == 'http://img3.abload.de/img/10nx2340fhco.gif' ||
$images[1][$i] == 'http://i42.tinypic.com/9pp2456x.gif')
{
unset($images[1][$i]);
}
}
var_dump($images);die();