Question

$array = array(
  'first element',
  'second element',
  'third element',
);

echo $array['1'];
echo $array[1];

They both produce the same result.

I am asking this question because I noticed for example drupal accesses the index as string literals, where as php.net uses integers.

Are there advantages of one over the other?

Of course I know why $array[foo] is bad.

Answer 1

It’s indifferent in terms of semantics.

When you do $array['string'] and 'string' is a number in base 10 without leading zeros and decimal point that fits on the integer range (i.e., is between -PHP_INT_MAX-1 and PHP_INT_MAX), it will be converted into an integer.

In terms of performance, it’s preferrable to use an integer directly because that will skip the conversion step.