Question

我想将数字转换为相应的字母。例如：

var select = document.getElementsByClassName('stat');
for(var i = 0; i < select.length; i++) {
  select[i].onchange = function () {
    this.className = this.options[this.selectedIndex].className;
  }
}

这可以在javascript中完成而无需手动创建数组吗？在php中有一个range（）函数可以自动创建数组。在javascript中有类似的东西吗？

Answer 1

是的，Number#toString(36)并进行调整。

＆＃13;

var value = 10;

document.write((value + 9).toString(36).toUpperCase());

＆＃13;

Answer 2

您可以使用String.fromCharCode(code)函数在没有数组的情况下执行此操作，因为字母具有连续代码。例如：String.fromCharCode(1+64)为您提供'A'，String.fromCharCode(2+64)为您提供'B'，依此类推。

Answer 3

下面的代码片段将字母转换为数字系统形式的字符

1 = A
2 = B
...
26 = Z
27 = AA
28 = AB
...
78 = BZ
79 = CA
80 = CB

KeyDown

我创建了此功能来保存打印时的字符，但由于我不想处理可能最终形成的不当字眼而不得不将其废弃

Answer 4

我构建了以下解决方案作为对@esantos 答案的增强。

第一个函数定义了一个有效的查找编码字典。在这里，我使用了英文字母表的所有 26 个字母，但以下也同样适用："ABCDEFG"、"ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"、"GFEDCBA"。使用这些字典之一将导致您的基数为 10 的数字转换为具有适当编码数字的基数 dictionary.length 数。唯一的限制是字典中的每个字符必须是唯一的。

function getDictionary() {
    return validateDictionary("ABCDEFGHIJKLMNOPQRSTUVWXYZ")

    function validateDictionary(dictionary) {
        for (let i = 0; i < dictionary.length; i++) {
            if(dictionary.indexOf(dictionary[i]) !== dictionary.lastIndexOf(dictionary[i])) {
                console.log('Error: The dictionary in use has at least one repeating symbol:', dictionary[i])
                return undefined
            }
        }
        return dictionary
    }
}

我们现在可以使用这本字典来编码我们的基数为 10 的数字。

function numberToEncodedLetter(number) {
    //Takes any number and converts it into a base (dictionary length) letter combo. 0 corresponds to an empty string.
    //It converts any numerical entry into a positive integer.
    if (isNaN(number)) {return undefined}
    number = Math.abs(Math.floor(number))

    const dictionary = getDictionary()
    let index = number % dictionary.length
    let quotient = number / dictionary.length
    let result
    
    if (number <= dictionary.length) {return numToLetter(number)}  //Number is within single digit bounds of our encoding letter alphabet

    if (quotient >= 1) {
        //This number was bigger than our dictionary, recursively perform this function until we're done
        if (index === 0) {quotient--}   //Accounts for the edge case of the last letter in the dictionary string
        result = numberToEncodedLetter(quotient)
    }

    if (index === 0) {index = dictionary.length}   //Accounts for the edge case of the final letter; avoids getting an empty string
    
    return result + numToLetter(index)

    function numToLetter(number) {
        //Takes a letter between 0 and max letter length and returns the corresponding letter
        if (number > dictionary.length || number < 0) {return undefined}
        if (number === 0) {
            return ''
        } else {
            return dictionary.slice(number - 1, number)
        }
    }
}

一组编码的字母很棒，但如果我不能将它转换回以 10 为基数的数字，它对计算机来说就毫无用处。

function encodedLetterToNumber(encoded) {
    //Takes any number encoded with the provided encode dictionary 

    const dictionary = getDictionary()
    let result = 0
    let index = 0

    for (let i = 1; i <= encoded.length; i++) {
        index = dictionary.search(encoded.slice(i - 1, i)) + 1
        if (index === 0) {return undefined} //Attempted to find a letter that wasn't encoded in the dictionary
        result = result + index * Math.pow(dictionary.length, (encoded.length - i))
    }

    return result
}

现在测试一下：

console.log(numberToEncodedLetter(4))     //D
console.log(numberToEncodedLetter(52))    //AZ
console.log(encodedLetterToNumber("BZ"))  //78
console.log(encodedLetterToNumber("AAC")) //705

更新

您还可以使用此函数来获取您拥有的短名称格式并将其返回为基于索引的格式。

function shortNameToIndex(shortName) {
    //Takes the short name (e.g. F6, AA47) and converts to base indecies ({6, 6}, {27, 47})

    if (shortName.length < 2) {return undefined}    //Must be at least one letter and one number
    if (!isNaN(shortName.slice(0, 1))) {return undefined}  //If first character isn't a letter, it's incorrectly formatted

    let letterPart = ''
    let numberPart= ''
    let splitComplete = false
    let index = 1

    do {
        const character = shortName.slice(index - 1, index)
        if (!isNaN(character)) {splitComplete = true}
        if (splitComplete && isNaN(character)) {
            //More letters existed after the numbers. Invalid formatting.
            return undefined    
        } else if (splitComplete && !isNaN(character)) {
            //Number part
            numberPart = numberPart.concat(character)
        } else {
            //Letter part
            letterPart = letterPart.concat(character)
        }
        index++
    } while (index <= shortName.length)

    numberPart = parseInt(numberPart)
    letterPart = encodedLetterToNumber(letterPart)

    return {xIndex: numberPart, yIndex: letterPart}
}

Answer 5

这可以帮到你

static readonly string[] Columns_Lettre = new[] { "A", "B", "C"};

public static string IndexToColumn(int index)
    {
        if (index <= 0)
            throw new IndexOutOfRangeException("index must be a positive number");

        if (index < 4)
            return Columns_Lettre[index - 1];
        else
            return index.ToString();
    }

将数字转换为字母

5 个答案: