Accessing arrays whitout quoting the key

Question

I can access an array value either with $array[key] or $array[\'key\']

Is there a reason to avoid using one over the other?

Answer 1

$array[key] is not correct usage. In this case 'key' will be treated as a constant (i.e., via define()) instead of a string. In the case where there is no constant named key, PHP will assume you mean 'key' and "fix" it for you and throw a warning.