standard / readable array declaration and using

Question

what in your opinion more standard / readable / efficient code of array declaration :

one way :

$days = array(1=>'Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat');

then use : $days[$value]

or the second way :

$days = array('Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat');

then use : $days[$value-1]

update : i cant sure that the values be in [0-6] , because that i dont offer 3 way.

Answer 1

Definitely the first one (when keys are correctly defined).

In the second one you need to do a minus (extract) this is an unnecessary cpu cycle makes your code less readable and less maintenable.

Edit: I hope all of you lazy programmers are happy out there.

Answer 2

How about the 3rd way:

$days = array('Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat');

and access it as:

$days[$value]

by ensuring that $value has value between [0,6]

Answer 3

a funny one:

$days = array('Zer','Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat');

(a friend of mine used a month name "Nulleary" once)
but seriously, it depends on where this array does come from.
For this particular example it should be just date("D",$tstamp);

though the whole problem negligible to me.
I am often using just

$days = explode(" ",'Sun Mon Tue Wed Thu Fri Sat');

and find it very handy.