Cannot use [] for reading

Question

In one of my scripts, I try to do the following

$data[] = self::get($row['sr_id']); // <-- line 55

However, PHP does not allow me to do this, giving me this error

Fatal error: Cannot use [] for reading in /file.php on line 55

The self::get function return either a bool, or an object.

Edit: The get function creates a new object which again loads data from a mysql database.

Try to find out whether the error is about `$data[] =` or about `$row['sr_id']`. — Sjoerd, Sep 29 '10 at 09:39

score 34 · Answer 1 · edited Feb 21 '12 at 09:45

34

The solution in my case was this:

Bad line:

$this->$ExtraTag[] = $fullscript;

Good line:

$this->{$ExtraTag}[] = $fullscript;

or

$this->ExtraTag[] = $fullscript;

edited Feb 21 '12 at 09:45

Community

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answered Nov 19 '11 at 12:25

SZL

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Sweet. $this->{$ExtraTag}[] = $fullscript worked for me! – FateNuller Jun 22 '15 at 16:01
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I'm not surprised the first "bad" line doesn't work and the last line does: the "bad" line is actually invalid syntax, and the last line is the intended syntax. The middle example is an ugly workaround to turn the first example into the third. I would recommend against that: it is less clear, less concise, and less performant (because PHP doesn't have a precompiler to optimise it away to the third example). – Byson Jul 21 '17 at 13:06
Great, but this doesn't solve the OP question. – Studocwho Jul 14 '23 at 03:00

score 24 · Accepted Answer · edited Jan 29 '14 at 17:41

24

Old PHP versions accepted $var[] in expressions, allowed reading out the $var content regardless of syntax. PHP 5.1 made that illegal. But sometimes the error is triggered outside of the intented context.
So my guess (again: show more code) is that the preceeding line contains an unfinished expression, to which the $data[] joins.

In case of object attribute you can wrap your $data var into { }, but that doesn't seem to be the problem in your case. (Else there is something in line 54, that you didn't show.) The right hand side can't reasonably trigger the error. Even array accessing [] an integer or object wouldn't trigger that fatal error.

So if nothing helps, just use array_push(). Work around PHP.

edited Jan 29 '14 at 17:41

aksu

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answered Sep 29 '10 at 12:36

mario

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Thanks, the `array_push()` function did the trick, now it works. :) – eriktm Sep 29 '10 at 18:15
Might be it, or perhaps the array was undefined or of a different type, which can cause this fatal error. (See below). – lucian303 Jun 10 '13 at 23:51

score 2 · Answer 3 · edited Sep 12 '16 at 06:46

The error I got was:

Fatal error: Cannot use [] for reading in /pathtosite/drupal/sites/all/themes/zenui/templates/page.tpl.php on line 33

Sometime the problem is when you include a line like this:

$page['sidebar_first'][]

This might happen if you are copying a variable name and forgot to comment out the line.

There was two problems:

1. Missing semicolon

2. $variable[] must set a variable

After fixing these two problems my code read:

$page['sidebar_first'][] = $value;

Don't forget to comment out line you are not using to help with the debugging process

Hope this helps fellow programmers like me!

score 1 · Answer 4 · answered Mar 10 '19 at 07:08

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I had same error with following:

echo implode(',', $array[]);

which should have been

echo implode(',', $array);

Hope this can help someone

answered Mar 10 '19 at 07:08

Michael Eugene Yuen

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score 0 · Answer 5 · edited Aug 19 '12 at 13:59

0

try:

$data = Array();
$data[] = self::get($row['sr_id']); // <-- line 55

edited Aug 19 '12 at 13:59

Rostyslav Dzinko

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answered Sep 29 '10 at 09:46

sathia

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Not initializing arrays will not cause a Fatal Error. – Russell Dias Sep 29 '10 at 09:48
it's alright, but if $data was previously an object or a var it may – sathia Sep 29 '10 at 09:52
then you know it's something on the other side: self::get($row['sr_id']); what does var_dump(self::get($row['sr_id'])); says? – sathia Sep 29 '10 at 10:21
Not initializing arrays can and _does_ cause a Fatal Error indeed, including in a simple expression such as {$arr['key']} – lucian303 Jun 10 '13 at 23:50

score 0 · Answer 6 · answered Jun 22 '17 at 18:05

0

I had the same problem with my script, the following line threw the same error:

$array[]=$value

I simply replaced it by

$array[count($array)-1]=$value

and it worked perfectly.

answered Jun 22 '17 at 18:05

Nino Filiu

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score 0 · Answer 7 · answered Jul 21 '17 at 13:02

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Another possible problem could be an accidental double ==. For example accidentally doing $myArray[] == $myNewValue; would cause this error (because you are trying to read a value with the == instead of telling PHP to assign a new array index).

answered Jul 21 '17 at 13:02

Byson

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Cannot use [] for reading

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