Illegal offset type

Description

PHP only uses integers and strings as array index. While certain other types may be converted silently to those types, as null or boolean, objects and arrays yield an illegal type for index.

This error is reported at compile time when PHP can detect the type then, otherwise, it is reported at execution time.

Example

<?php

$a = new Stdclass;

$array = [$a => 2];

$array[$a] = 1;

$array[$array] = 3;

?>

Solutions

  • Convert these types into a string or a integer first.

  • Cast these types into a string or a integer first.