Fatal error: Uncaught Error: Cannot use a scalar as an array warning

Question

I have the following code:

 $final = [1 => 2];
 $id = 1;

 $final[$id][0] = 3;

The code seems to work fine, but I get this warning:

Warning: Cannot use a scalar value as an array in line X (the line with: $final[$id][0] = 3).

Can anyone tell me how to fix this?

Answer 1

You need to set$final[$id] to an array before adding elements to it. Intiialize it with either

$final[$id] = array();
$final[$id][0] = 3;
$final[$id]['link'] = "/".$row['permalink'];
$final[$id]['title'] = $row['title'];

or

$final[$id] = array(0 => 3);
$final[$id]['link'] = "/".$row['permalink'];
$final[$id]['title'] = $row['title'];

Answer 2

The reason is because somewhere you have first declared your variable with a normal integer or string and then later you are trying to turn it into an array.

Answer 3

The Other Issue I have seen on this is when nesting arrays this tends to throw the warning, consider the following:

$data = [
"rs" => null
]

this above will work absolutely fine when used like:

$data["rs"] =  5;

But the below will throw a warning ::

$data = [
    "rs" => [
       "rs1" => null;
       ]
    ]
..

$data[rs][rs1] = 2; // this will throw the warning unless assigned to an array

Answer 4

Also make sure that you don't declare it an array and then try to assign something else to the array like a string, float, integer. I had that problem. If you do some echos of output I was seeing what I wanted the first time, but not after another pass of the same code.