PHP-阵列致命错误

Question

I've got an odd error in my PHP code regarding dynamic arrays.

The error outputted is:

Fatal error: Cannot use string offset as an array ... on line 89

This is a portion of my code, it is within a foreach loop, which is looping through settings in a database:

foreach($query->fetchAll() as $row)
{
    if($site!=CURRENT_SITE_TEMPLATE)
    {
        $property = 'foreignSettings';
        $propertyType = 'foreignSettingsTypes';
    } else {
        $property = 'settings';
        $propertyType = 'settingTypes';
    }

    $this->$property[$row['variable_section']][$row['variable_name']] = $row['variable_value'];
    settype($this->$property[$row['variable_section']][$row['variable_name']],$row['variable_type']);

    $this->$propertyType[$row['variable_section']][$row['variable_name']] = $row['variable_type'];
}

For the sake of the example code, $site is 'admin' and CURRENT_SITE_TEMPLATE is 'admin'. In addition, $foreignSettings, $foreignSettingsTypes, $settings, and $settingTypes are all defined as arrays in the class scope

The error is on line 89, which is:

$this->$property[$row['variable_section']][$row['variable_name']] = $row['variable_value'];

I originally thought it was because of the $property variable accesing the array, however, this looks like valid legal code in the PHP documentation ( http://php.net/manual/en/language.variables.variable.php in example #1 )

Any help on this error would be appreciated.

Thanks

Answer 1

In your given example $property is a string. You are then trying to use that as an array. Strings only has numeric indexes (if you need to use as an array).

Answer 2

The problem is as follows: $this->$property[0] means you access the 0th place of $property which in your case would be the first letter of the string $property. Thus you end up with $this->f or $this->s.

with $this->$property[0][0] you would be trying to access the 0th place of the 0th place of the $property string what results in an error because you try to access the 0th place of the char s what is not possible since the char s can not be referenced as an array.

what you want is $this->{$propperty}[0][0] what means that you try to access the 0th place of the 0th place of the variable that has the name $propperty.