Cannot Use String Offset as Array

Why This Happens

In PHP, strings support bracket access for individual characters like $str[0]. If you try to use nested brackets like $str['key']['subkey'] on a string, PHP cannot treat a character as an array. This often happens when a variable is overwritten from an array to a string unexpectedly.

The Problem

$data = '';
$data['users']['admin'] = 'Alice'; // $data is a string, not an array

The Fix

$data = [];
$data['users']['admin'] = 'Alice';

Step-by-Step Fix

1. 1

   Check the variable type

   Use var_dump() to inspect the variable. It is likely a string where you expected an array.

2. 2

   Find where the type changed

   Trace the variable's assignments to find where it was set to a string instead of being initialized as an array.

3. 3

   Initialize as array

   Ensure the variable is initialized as an empty array [] before using nested array assignment syntax.