How to remove a variable from a PHP session array
PhpArraysSessionPhp Problem Overview
I have PHP code that is used to add variables to a session:
<?php
session_start();
if(isset($_GET['name']))
{
$name = isset($_SESSION['name']) ? $_SESSION['name'] : array();
$name[] = $_GET['name'];
$_SESSION['name'] = $name;
}
if (isset($_POST['remove']))
{
unset($_SESSION['name']);
}
?>
<pre> <?php print_r($_SESSION); ?> </pre>
<form name="input" action="index.php?name=<?php echo $list ?>" method="post">
<input type="submit" name ="add"value="Add" />
</form>
<form name="input" action="index.php?name=<?php echo $list2 ?>" method="post">
<input type="submit" name="remove" value="Remove" />
</form>
I want to remove the variable that is shown in $list2
from the session array when the user chooses 'Remove'.
But when I unset, ALL the variables in the array are deleted.
How I can delete just one variable?
Php Solutions
Solution 1 - Php
if (isset($_POST['remove'])) {
$key=array_search($_GET['name'],$_SESSION['name']);
if($key!==false)
unset($_SESSION['name'][$key]);
$_SESSION["name"] = array_values($_SESSION["name"]);
}
Since $_SESSION['name']
is an array, you need to find the array key that points at the name value you're interested in. The last line rearranges the index of the array for the next use.
Solution 2 - Php
To remove a specific variable from the session use:
session_unregister('variableName');
(see documentation) or
unset($_SESSION['variableName']);
NOTE:
session_unregister()
has been DEPRECATED as of PHP 5.3.0 and REMOVED as of PHP 5.4.0.
Solution 3 - Php
Is the $_SESSION['name'] variable an array? If you want to delete a specific key from within an array, you have to refer to that exact key in the unset() call, otherwise you delete the entire array, e.g.
$name = array(0 => 'a', 1 => 'b', 2 => 'c');
unset($name); // deletes the entire array
unset($name[1]); // deletes only the 'b' entry
Another minor problem with your snippet: You're mixing GET query parameters in with a POST form. Is there any reason why you can't do the forms with 'name' being passed in a hidden field? It's best to not mix get and post variables, especially if you use $_REQUEST elsewhere. You can run into all kinds of fun trying to figure out why $_GET['name'] isn't showing up the same as $_POST['name'], because the server's got a differnt EGPCS order set in the 'variables_order' .ini setting.
<form blah blah blah method="post">
<input type="hidden" name="name" value="<?= htmlspecialchars($list1) ?>" />
<input type="submit" name="add" value="Add />
</form>
And note the htmlspecialchars() call. If either $list1 or $list2 contain a double quote ("), it'll break your HTML
Solution 4 - Php
If you want to remove or unset all $_SESSION 's then try this
session_destroy();
If you want to remove specific $_SESSION['name'] then try this
session_unset('name');
Solution 5 - Php
Currently you are clearing the name array, you need to call the array then the index you want to unset within the array:
$ar[0]==2
$ar[1]==7
$ar[2]==9
unset ($ar[2])
Two ways of unsetting values within an array:
<?php
# remove by key:
function array_remove_key ()
{
$args = func_get_args();
return array_diff_key($args[0],array_flip(array_slice($args,1)));
}
# remove by value:
function array_remove_value ()
{
$args = func_get_args();
return array_diff($args[0],array_slice($args,1));
}
$fruit_inventory = array(
'apples' => 52,
'bananas' => 78,
'peaches' => 'out of season',
'pears' => 'out of season',
'oranges' => 'no longer sold',
'carrots' => 15,
'beets' => 15,
);
echo "<pre>Original Array:\n",
print_r($fruit_inventory,TRUE),
'</pre>';
# For example, beets and carrots are not fruits...
$fruit_inventory = array_remove_key($fruit_inventory,
"beets",
"carrots");
echo "<pre>Array after key removal:\n",
print_r($fruit_inventory,TRUE),
'</pre>';
# Let's also remove 'out of season' and 'no longer sold' fruit...
$fruit_inventory = array_remove_value($fruit_inventory,
"out of season",
"no longer sold");
echo "<pre>Array after value removal:\n",
print_r($fruit_inventory,TRUE),
'</pre>';
?>
So, unset has no effect to internal array counter!!!
Solution 6 - Php
Try this one:
if(FALSE !== ($key = array_search($_GET['name'],$_SESSION['name'])))
{
unset($_SESSION['name'][$key]);
}
Solution 7 - Php
Simply use this method.
<?php
$_SESSION['foo'] = 'bar'; // set session
print $_SESSION['foo']; //print it
unset($_SESSION['foo']); //unset session
?>