Convert the name of an Excel column to number

JavaScript

const getIndex = (col) => col.split('').reduce((prev, next) => prev * 26 + parseInt(next, 36) - 9, 0)

TypeScript

const getIndex = (col: string): number => col.split('').reduce((prev, next) => prev * 26 + parseInt(next, 36) - 9, 0)

Examples

getIndex('A') // 1
getIndex('B') // 2
getIndex('C') // 3
getIndex('Z') // 26

getIndex('AA') // 27
getIndex('AB') // 28
getIndex('AC') // 29
getIndex('AZ') // 52

getIndex('AAA') // 703
getIndex('AAB') // 704