在Ruby中将excel列字母转换为整数

Question

将类似excel的列字母转换为整数的最简单方法是什么？

例如:

AB --> 27
AA --> 26
A --> 0
Z --> 25

Answer 1

def excel_col_index( str )
  value = Hash[ ('A'..'Z').map.with_index.to_a ]
  str.chars.inject(0){ |x,c| x*26 + value[c] + 1 }
end

要么

def excel_col_index( str )
  offset = 'A'.ord - 1
  str.chars.inject(0){ |x,c| x*26 + c.ord - offset }
end

Answer 2

我会做这样的事情:

def column_name_to_number(column_name)
  multipliers = ('A'..'Z').to_a
  chars = column_name.split('')

  chars.inject(-1) { |n, c| multipliers.index(c) + (n + 1) * 26 }
end