i want to be able to change the last key from array
i try with this function i made:
function getlastimage($newkey){
$arr = $_SESSION['files'];
$oldkey = array_pop(array_keys($arr));
$arr[$newkey] = $arr[$oldkey];
unset($arr[$oldkey]);
$_SESSION['files'] = $arr;
$results = end($arr);
print_r($arr);
}
if i call the function getlastimage('newkey') it change the key!but after if i print the $_SESSION the key is not changed? why this?
When you set $arr = $_SESSION['files'], you are actually making a copy of $_SESSION['files']. Everything you do to $arr is not done to the original.
Try this:
$arr =& $_SESSION['files'];
Note the ampersand after the equals sign. That will make $arr a reference to $_SESSION['files'], and your updates to $arr will affect $_SESSION['files'] as well, since they both reference the same content.
The other solution is of course to just copy the array back by putting $_SESSION['files'] = $arr; at the end of your function.
Wow, your code is a mess!
1) You're setting $_SESSION in a new array. In order for your changes to take affect, you'll need to set back to your original $_SESSION array, otherwise your new array will just be forgotten.
2) It would be easier to simply array_pop() to get the last element and set it to the new key, rather than wasting the time to fetch all the keys and pop the last key off, then fetch the value from the array again. The old key value is worthless.
try update the session
$_SESSION['files'] = $arr;
Related
when in use json_decod with option "JSON_FORCE_OBJECT" its return out put index started with 0 and its true but i need to start the out put index with 1 so how i can fix my problem?
json_encode($request->get('poll_items'), JSON_FORCE_OBJECT)
The output result is and current BUT:
"{"0":"option1","1":"option2","2":"option3"}"
I need to return like this:
"{"1":"option1","2":"option2","3":"option3"}"
Thank you.
An easy solution would be to use array_unshift() and unset():
$array = $request->get('poll_items');
// Add an element to the beginning
array_shift($array, '');
// Unset the first element
unset($array[0]);
Now you're left with an associative array that starts with 1.
Here's a demo
My first question would be why do you need this to be 1 indexed instead of 0?
If this data is consumed outside of your control then you could map the data across to another array and encode that instead. For example:
$newArray = array();
foreach ($request->get('poll_items') as $index => $value) {
$newArray[++$index] = $value
}
$output = json_encode($newArray, JSON_FORCE_OBJECT);
NOTE: ++$index instead of $index++ as the latter will only alter the value after the line has computed.
I have an array that I would like to clear the values out of and I'm wondering what the best way to accomplish this is.
I tried setting it to nothing:
$array = array();
... later on
$array = "";
Afterwards I'll add new values to it later:
foreach($something as $thing):
$array[] = $thing['item'];
endforeach;
And it seems to have done what I needed it too. But after a quick search online I'm seeing a lot of recommendations to do the following instead:
unset($array);
$array = array();
Is there any difference between this action and the one I performed up top?
Setting $array to "" sets your variable to a string value, and unset removes the variable. Since you are just trying to clear the array, then $array = array() should be good enough.
I believe that array() explicitly defines it as an array. Your first statement $array = "" sets it to an empty string. Using unset will "reset" the variable, so it's neither a string or array until you assign a value to it, and $array = array() simply defines it as a new blank array.
how to slice an array to pass it to a function. I cannot use unset because I need that array further. I know I can copy whole array to variable, however it's quite big and don't thing it's efficient. My code:
$list = array(0=>2123, 2=>1231, 7=>123123,...);
unset($list[0]); //I can't do this because I still need whole $list
$seats = $allocatingClass->allocateSeats($seatsNumber, $list); //here I need to slice $key from $list and pass $list without reiterating
If you need to keep index 0, store it, rather than storing the entire array elsewhere:
$tmp = $list[0];
Then splice the array:
$list = array_splice($list,1,count($list));
Then pass it to your function:
$seats = $allocatingClass->allocateSeats($seatsNumber, $list);
Then, when you need it, put back the value to the array:
$list[] = $tmp;
Edit: if you actually need to put it exactly at index 0, then you may want to unset the index 0 of the array instead of splicing it. If you can, however, push it at the end of the array just follow what is written above.
To clearify, if you need to LATER push back the element to index 0, do
unset($list[0]);
instead of the splice...
And to put back the element, do:
$list[0] = $tmp;
However you do it, a copy will be made when passing the array (unless you pass it by reference).
either use splice. or create a copy and shift one value.
after sending the copy variable, you can unset it so it wont keeptaking its space.
Edit :
The above solution is also viable. Though I suggest you use:
$tmp = array_shift($arr);
doStuf($arr);
array_unshift($arr, $tmp);
I will always unset an array value in my Site request.
unset($segments[0]);
How can I push back the arrays, so I get the "1" key to be the "0"?
Example:
$arr[0] = 'Balls';
$arr[1] = 'Test';
unset($arr[0]);
(magicalfunctionthatpushback)
echo $arr[0]; //Test
There must be a function for this or do I need to use a for loop?
Use array_shift to remove the element instead of unset.
There's also the array_values function to get a new array reindexed from zero. I would choose array_shift() in your scenario though.
I want to add an element to the beginning of an array, but this array might be empty sometimes. I've tried using array_unshift() but it doesn't seem to like empty arrays... should I simply check for the empty array and append the element manually, or does array_unshift() not mind empty arrays but I'm just being a klutz?
Here is my code at the moment:
$sids = array();
$sids = explode(",", $sid['sids']);
array_unshift($sids, session_id());
The contents of the $sids array are taken from a database and are comma separated values.
Thanks,
James
EDIT
I've managed to fix this now - sorry everyone!
Here's the updated code:
$sids = array();
if(!empty($row['sids']))
{
$sids = explode(",", $row['sids']);
}
array_unshift($sids, session_id());
If $sid['sids'] is empty, explode will return FALSE
Then $sids will be equal to FALSE
and the subsequent call to array_unshift will fail.
You should probably make sure $sids is an array before calling array_unshift.
Here's a way to do it:
if(!empty($sid['sids']))
$sids = explode(",", $sid['sids']);
else
$sids = array();
array_unshift($sids, session_id());
First off, your first line of code is pointless; explode always returns a value, whether it be an array or FALSE. You're guaranteed to overwrite that value once you call explode.
Secondly, your code should work. One minor edit I'd make is this:
<?php
$sids = array();
$sids = explode(",", $sid['sids']);
if(is_array($sids))
array_unshift($sids, session_id());
?>
Because (even though your code says otherwise, and that the PHP documentation says otherwise), explode may not always return an array.
Another piece of information that may be useful is whether or not there was any error being reported, and, if so, what the error was.
Best of luck!
array_unshift() accepts the array parameter by reference. This means it must actually be a variable, not an expression like array(). It also means it will modify the variable you pass, not return a new array with the element added. Here's an example to illustrate this:
$array = array();
array_unshift($array, 42);
var_dump($array); // Array now has one element, 42
$sids = explode(",", $sid['sids']);
if (!is_array($sids)) {
$sids = array();
}
array_unshift($sids, session_id());