Cannot use string offset as an array in php

Question

I\'m trying to simulate this error with a sample php code but haven\'t been successful. Any help would be great.

\"Cannot use string offset as an array\"

Answer 1

I believe what are you asking about is a variable interpolation in PHP.

Let's do a simple fixture:

$obj = (object) array('foo' => array('bar'), 'property' => 'value');
$var = 'foo';

Now we have an object, where:

print_r($obj);

Will give output:

stdClass Object
    (
        [foo] => Array
            (
                [0] => bar
            )

        [property] => value
    )

And we have variable $var containing string "foo".

If you'll try to use:

$give_me_foo = $obj->$var[0];

Instead of:

$give_me_foo = $obj->foo[0];

You get "Cannot use string offset as an array [...]" error message as a result, because what you are trying to do, is in fact sending message $var[0] to object $obj. And - as you can see from fixture - there is no content of $var[0] defined. Variable $var is a string and not an array.

What you can do in this case is to use curly braces, which will assure that at first is called content of $var, and subsequently the rest of message-sent:

$give_me_foo = $obj->{$var}[0];

The result is "bar", as you would expect.

Answer 2

I just want to explain my solving for the same problem.

my code before(given same error):

$arr2= ""; // this is the problem and solve by replace this $arr2 = array();
for($i=2;$i<count($arrdata);$i++){
    $rowx = explode(" ",$arrdata[$i]);
    $arr1= ""; // and this is too
    for($x=0;$x<count($rowx);$x++){
        if($rowx[$x]!=""){
            $arr1[] = $rowx[$x];
        }
    }
    $arr2[] = $arr1;
}
for($i=0;$i<count($arr2);$i++){
    $td .="<tr>";
    for($j=0;$j<count($hcol)-1;$j++){
        $td .= "<td style='border-right:0px solid #000'>".$arr2[$i][$j]."</td>"; //and it's($arr2[$i][$j]) give an error: Cannot use string offset as an array
    }
    $td .="</tr>";
}

my code after and solved it:

$arr2= array(); //change this from $arr2="";
for($i=2;$i<count($arrdata);$i++){
    $rowx = explode(" ",$arrdata[$i]);
    $arr1=array(); //and this
    for($x=0;$x<count($rowx);$x++){
        if($rowx[$x]!=""){
            $arr1[] = $rowx[$x];
        }
    }
    $arr2[] = $arr1;
}
for($i=0;$i<count($arr2);$i++){
    $td .="<tr>";
    for($j=0;$j<count($hcol)-1;$j++){
        $td .= "<td style='border-right:0px solid #000'>".$arr2[$i][$j]."</td>";
    }
    $td .="</tr>";
}

Thank's. Hope it's helped, and sorry if my english mess like boy's room :D

Answer 3

For PHP4

...this reproduced the error:

$foo    = 'bar';
$foo[0] = 'bar';

For PHP5

...this reproduced the error:

$foo = 'bar';

if (is_array($foo['bar']))
    echo 'bar-array';
if (is_array($foo['bar']['foo']))
    echo 'bar-foo-array';
if (is_array($foo['bar']['foo']['bar']))
    echo 'bar-foo-bar-array';

(From bugs.php.net actually)

Edit,

so why doesn't the error appear in the first if condition even though it is a string.

Because PHP is a very forgiving programming language, I'd guess. I'll illustrate with code of what I think is going on:

$foo = 'bar';
// $foo is now equal to "bar"

$foo['bar'] = 'foo';
// $foo['bar'] doesn't exists - use first index instead (0)
// $foo['bar'] is equal to using $foo[0]
// $foo['bar'] points to a character so the string "foo" won't fit
// $foo['bar'] will instead be set to the first index
// of the string/array "foo", i.e 'f'

echo $foo['bar'];
// output will be "f"

echo $foo;
// output will be "far"

echo $foo['bar']['bar'];
// $foo['bar'][0] is equal calling to $foo['bar']['bar']
// $foo['bar'] points to a character
// characters can not be represented as an array,
// so we cannot reach anything at position 0 of a character
// --> fatal error

Answer 4

I was able to reproduce this once I upgraded to PHP 7. It breaks when you try to force array elements into a string.

$params = '';
foreach ($foo) {
  $index = 0;
  $params[$index]['keyName'] = $name . '.' . $fileExt;
}

After changing:

$params = '';

to:

$params = array();

I stopped getting the error. I found the solution in this bug report thread. I hope this helps.