What is the error message "Fatal error: [] operator not supported for strings" in PHP indicating?

The error message "Fatal error: [] operator not supported for strings" in PHP indicates that you are trying to use the array index operator [] on a string variable, which is not allowed. To solve this issue, you need to make sure that you are only using the [] operator on arrays, not strings.

// Incorrect usage of [] operator on a string variable
$string = "Hello";
$value = $string[0];

// Correct usage by converting the string to an array
$string = "Hello";
$array = str_split($string);
$value = $array[0];