Parse error: syntax error, unexpected 'unset' (T_UNSET)

Question

I am using simple php unset() function to remove and index of array but it's showing the following error:

Parse error: syntax error, unexpected 'unset' (T_UNSET)

Here is my erroneous code:

echo $totalArray = unset($linkExtHelp[0]);

Thanks in advance.

score 25 · Accepted Answer · edited Sep 09 '20 at 09:51

25

Try this, Reason for unset($linkExtHelp[0]) assigning to the variable echo $totalArray = You can't assign the unset() value to the variable, You can use to check before unset and after unset as like below. In other words, unset does not have any return value, since unset is a void. Void - does not provide a result value to its caller.

Syntax: void unset ( mixed $var [, mixed $... ] )

echo "Before unset: ".$linkExtHelp[0];
unset($linkExtHelp[0]);
$linkExtHelp = array_values($linkExtHelp);
echo "After unset: ".$linkExtHelp[0];

instead of

echo $totalArray  =     unset($linkExtHelp[0]);

edited Sep 09 '20 at 09:51

MartinNajemi

514
3
18

answered Jan 30 '14 at 06:47

Krish R

22,583
7
50
59

1

Nit: `unset` *isn't* a function. A *real* [void] function would have resulted in a different error. – user2864740 Jan 30 '14 at 07:41
May i know what is the error in this code : https://www.pastiebin.com/5d319d2506c52 i am getting same error like ( ! ) Parse error: syntax error, unexpected 'unset' (T_UNSET) in C:\wamp\www\voice_bank\playlist_action.php on line 11 – Gem Jul 19 '19 at 10:37

user2864740 · Answer 2 · 2014-01-30T19:59:41.193

unset does not return a value - it cannot be used meaningfully as an expression, even if such a production was accepted.

However, the parse error is caused because unset is a keyword and a "special production": even though unset looks like a function, it is not a function¹. As such, unset is only valid as a statement² per the language grammar.

The production can be found in zend_language_parser.y:

309 unticked_statement:
       |   ..
338    |   T_UNSET '(' unset_variables ')' ';'

¹ The syntax is due to historical design choices, and arguably a mistake from a consistency viewpoint:

Note: Because [unset] is a language construct and not a function, it cannot be called using variable functions.

² There is also "(unset) casting", but I'm ignoring that here.

MartinNajemi · Answer 3 · 2020-09-08T16:46:10.487

1

Unset does not return anything, it is a keyword.

I assume you want to re-index the array, you can use array_values to do this

Try this:

unset($linkExtHelp[0]);
$totalArray = array_values($linkExtHelp);

edited Sep 08 '20 at 16:46

answered Jul 30 '20 at 18:01

MartinNajemi

514
3
18

What does this add that the existing and accepted answers don't have? – Jason Aller Jul 30 '20 at 19:34
@JasonAller The existing answer will leave the array missing a first value, my answer re-indexes (reassigns keys for the values) – MartinNajemi Aug 04 '20 at 14:44

score 0 · Answer 4 · answered Jun 30 '16 at 04:49

You can't assign "unset". this is how I do. you need to make a temp array.

 $totalArray  = $linkExtHelp; // assign it to a new array (so you can keep the original one )

 foreach ($totalArray  as $key => $value) {
 unset($totalArray  [$key]['save_day']); // if you need to remove all of 'save_day' value from multi array
 }
 var_dump($totalArray); // after unset
 var_dump($linkExtHelp); // the original array


 //echo $totalArray  =     unset($linkExtHelp[0]); // This is wrong. no echo

I hope it helps.

Parse error: syntax error, unexpected 'unset' (T_UNSET)

4 Answers4

Unset does not return anything, it is a keyword.