Description:
------------
When explaining array index types, the docs for the array type http://www.php.net/manual/en/language.types.array.php say:

'Strings containing valid integers will be cast to the integer type. E.g. the key "8" will actually be stored under 8. On the other hand "08" will not be cast, as it isn't a valid decimal integer.'

Taken literally, that paragraph would imply that the key '07', which is a valid integer, will be cast to the integer 7. However, that's not the case. $a['07'] does not reference the same element as $a[7].

The last qualification of 'decimal' integer gives a hint of what the actual intention of that paragraph was. It's possible to change the wording to "Strings containing valid decimal integers..." and to change the example to use 7 instead of 8, to leave it clearer how that excludes numbers with leading zeros no matter their validity as octal numbers. But that's not accurate enough either. Formally, +3 is a valid decimal integer, yet $a['+3'] doesn't reference the same element as $a[3].

It could say that the key is only cast to integer when a conversion of the string to integer and back to a decimal string gives the original string. The wording can become somewhat confusing though, just as the former statement is.

In past the wording seemed to be that if it's the standard representation of an integer then it's cast to integer. That seems more accurate than the current wording, yet still a bit confusing because there's no definition of standard representation.