Cannot use [] for reading

I had same error with following:

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

which should have been

echo implode(',', $array);

Hope this can help someone

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.

The solution in my case was this:

• Bad line:

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

• Good line:

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

or

$this->ExtraTag[] = $fullscript;

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!