JavaScript中的类似Excel的标题

Question

我正在尝试编写一个函数,它发出一系列字符串以匹配Excel上的标题.如果您不熟悉Excel,则该序列如下所示:

A,B,...,Z,AA,...,AZ,BA,...,ZZ,AAA,...,etc.

这是我提出的代码:

function next(id) {
    if(id === "")
        return "A";
    var prefix = id.substring(0, id.length-1);
    var last = id[id.length-1]
    if(last === "Z")
        return (next(prefix) + "A");
    return prefix + String.fromCharCode(id.charCodeAt(id.length-1) + 1);
}

你知道更好/更清洁的方式吗？

Answer 1

写了一点东西给你做这个问题，我觉得很清楚，也比较好用，有测试

所以你只需要为 A、B、C、D 调用“toExcelHeaderString(4)”

或对于 D 的单个 excel 行“toExcelHeader(4)”

/**
 * @param {Number} rows
 * @returns {String}
 */
toExcelHeaderString = function (rows) {
    return toExcelHeaderArray(rows).join(",");
}

// toExcelHeaderString(60) == "A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,AA,AB,AC,AD,AE,AF,AG,AH,AI,AJ,AK,AL,AM,AN,AO,AP,AQ,AR,AS,AT,AU,AV,AW,AX,AY,AZ,BA,BB,BC,BD,BE,BF,BG,BH"

/**
 * @param {Number} rows
 * @returns {Array}
 */
toExcelHeaderArray = function (rows) {
    var excelHeaderArr = [];
    for(var index = 1; index <= rows; index++) {
        excelHeaderArr.push(toExcelHeader(index));
    }
    return excelHeaderArr;
}

toExcelHeaderArray(60) == ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "AA", "AB", "AC", "AD", "AE", "AF", "AG", "AH", "AI", "AJ", "AK", "AL", "AM", "AN", "AO", "AP", "AQ", "AR", "AS", "AT", "AU", "AV", "AW", "AX", "AY", "AZ", "BA", "BB", "BC", "BD", "BE", "BF", "BG", "BH"]

/**
 * @param {Number} index
 * @returns {String}
 */
toExcelHeader = function (index) {
    if(index <= 0) {
        throw new Error("index must be 1 or greater");
    }
    index--;
    var charCodeOfA = ("a").charCodeAt(0); // you could hard code to 97
    var charCodeOfZ = ("z").charCodeAt(0); // you could hard code to 122
    var excelStr = "";
    var base24Str = (index).toString(charCodeOfZ - charCodeOfA + 1);
    for(var base24StrIndex = 0; base24StrIndex < base24Str.length; base24StrIndex++) {
        var base24Char = base24Str[base24StrIndex];
        var alphabetIndex = (base24Char * 1 == base24Char) ? base24Char : (base24Char.charCodeAt(0) - charCodeOfA + 10);
        // bizarre thing, A==1 in first digit, A==0 in other digits
        if(base24StrIndex == 0) {
            alphabetIndex -= 1;
        }
        excelStr += String.fromCharCode(charCodeOfA*1 + alphabetIndex*1);
    }
    return excelStr.toUpperCase();
}
// toExcelHeader(0) == Error
// toExcelHeader(1) == "A"
// toExcelHeader(26) == "Z"
// toExcelHeader(27) == "AA"
// toExcelHeader(3400) == "EAT"
// toExcelHeader(2048) == "CAT"
// toExcelHeader(3733849) == "HELLO"
// toExcelHeader(10768294) == "WORLD"