Php associative array for offset from 1 to 26

I am trying to create an associative array with alphabets as keys and 1 to 26 as values which I need to use to find the offset of alphabet from 1. So array['a'] would give me 1 and array['c'] would give me 3. Is there a way to declare such an array without typing in all ch开发者_Python百科aracters 1 by 1 as in

array('a' => 1, 'b' =>2, 'c'=>3 .... and so on

Or is there another way to get offset for alphabet from 1 to 26

You could do this using array_combine() and range():

array_combine(range('a', 'z'), range(1, 26));

No need to build the array, use like following -

$index = ord($input_char) - ord('a') + 1;

You can use chr and ord:

chr(97);  // a
chr(122); // z
ord('a'); // 97
ord('z'); // 122

arr = array();
for($i=1; $i<=26; ++$i) {
    arr(chr(96+$i)) = $i;
}