Excel表风格的字母列名转换为序号数字 Convert excel column name to number in javascript

excel column name to number.js

/**
 * Excel表风格的字母列名转换为序号数字
 * Excel spreadsheet style column names are like A,B,C...,AA,AB,AC,...etc
 * Sometimes we need to convert the letters name to number 1,2,3...,27,28,29,...etc
 * Author: https://github.com/cuixiping
**/

//solution 1: best performance and best compatibility
function lettersToNumber(letters){
    var chrs = ' ABCDEFGHIJKLMNOPQRSTUVWXYZ', mode = chrs.length - 1, number = 0;
    for(var p = 0; p < letters.length; p++){
        number = number * mode + chrs.indexOf(letters[p]);
    }
    return number;
}

//solution 2: short code (es6 arrow function)
function lettersToNumber(letters){
    return letters.split('').reduce((r, a) => r * 26 + parseInt(a, 36) - 9, 0);
}


//test:
['A', 'Z', 'AA', 'AB', 'ZZ','BKTXHSOGHKKE'].map(lettersToNumber);
// [1, 26, 27, 28, 702, 9007199254740991]

lettersToNumber('AAA'); //703