我想将一个数字转换为其对应的字母。例如：
1 = A
2 = B
3 = C
可以在 javascript 中完成此操作，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。 javascript 中有类似的东西吗？
Number#toString(36)var value = 10;
document.write((value + 9).toString(36).toUpperCase());您可以使用
String.fromCharCode(code)String.fromCharCode(1+64)String.fromCharCode(2+64)下面的代码片段将字母表中的字符转变为像数字系统一样工作
1 = A
2 = B
...
26 = Z
27 = AA
28 = AB
...
78 = BZ
79 = CA
80 = CB
var alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
var result = ""
function printToLetter(number){
var charIndex = number % alphabet.length
var quotient = number/alphabet.length
if(charIndex-1 == -1){
charIndex = alphabet.length
quotient--;
}
result = alphabet.charAt(charIndex-1) + result;
if(quotient>=1){
printToLetter(parseInt(quotient));
}else{
console.log(result)
result = ""
}
}
我创建了这个函数来在打印时保存字符，但不得不废弃它，因为我不想处理最终可能形成的不正确的单词
只需将 letterIndex 从 0 (A) 增加到 25 (Z)
const letterIndex = 0
const letter = String.fromCharCode(letterIndex + 'A'.charCodeAt(0))
console.log(letter)
更新（5/2/22）：在我在第二个项目中需要此代码后，我决定增强以下答案并将其转换为一个名为
alphanumeric-encoder我构建了以下解决方案作为对 @esantos 答案的增强。
第一个函数定义一个有效的查找编码字典。在这里，我使用了英文字母表中的全部 26 个字母，但以下字母也同样有效：
"ABCDEFG""ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789""GFEDCBA"dictionary.lengthfunction 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个字典来编码我们的 10 基数。
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)
}
}
}
编码的字母集很棒，但如果我不能将其转换回以 10 为基数的数字，那么它对计算机来说就没用了。
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}
}
有一个单行函数
numAbbr1 => A
2 => B
...
26 => Z
27 => AA
28 => AB
...
702 => ZZ
703 => AAA
const numAbbr = num => num <= 0 ? '' : numAbbr(Math.floor((num - 1) / 26)) + String.fromCharCode((num - 1) % 26 + 65);
相反的函数
abbrNumAAA
const abbrNum = abbr => abbr.toUpperCase().split("").reduce((acc, val) => acc * 26 + val.charCodeAt(0) - 64, 0);
这个问题的代码答案确实过于复杂，可以用一个简单的循环来实现
function colToLetter(number){
let result = '';
// number = number - 1; // If starting from 1
do {
const letter = String.fromCharCode(65 + (number % 26));
result = letter + result;
number = Math.floor(number / 26) - 1;
} while (number >= 0)
return result;
}
console.log(colToLetter(0));
console.log(colToLetter(25));
console.log(colToLetter(26));
console.log(colToLetter(702));
console.log(colToLetter(728));这提供了类似Excel的编号功能
String.fromCharCode(code)var index = 1;
console.log(String.fromCharCode(index + 64));
这可以帮助你
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();
}