Convert A to 1 B to 2 … Z to 26 and then AA to 27 AB to 28 (column indexes to column references in Excel)

Question

Does any one have algorithm or logic to Convert A to 1 ,B to 2, ... ,Z to 26 and then ,AA to 27, AB to 28 etc.

In other words, converting a column index into the col

Answer 1

Same problem, different language: PHP.

function charToInt($char)
{
   $array = array_flip(range(a, z));
   return $array[$char] + 1;
}

echo charToInt('c');

outputs: 3