什么方法可以用来增加字母?

Does anyone know of a Javascript library (e.g. underscore, jQuery, MooTools, etc.) that offers a method of incrementing a letter?

有谁知道Javascript库(例如下划线、jQuery、MooTools等)提供递增字母的方法吗?

I would like to be able to do something like:

我想做的是:

"a"++; // would return "b"

8 个解决方案

#1

119

function nextChar(c) {
    return String.fromCharCode(c.charCodeAt(0) + 1);
}
nextChar('a');

#2

Plain javascript should do the trick:

简单的javascript就可以做到:

String.fromCharCode('A'.charCodeAt() + 1) // Returns B

#3

What if the given letter is z? Here is a better solution. It goes A,B,C... X,Y,Z,AA,AB,... etc. Basically it increments letters like the column ID's of an Excel spreadsheet.

如果给定的字母是z呢?这里有一个更好的解决方案。它是A,B,C…X,Y,Z、AA、AB,……等等。基本上它会增加字母，比如Excel电子表格的列ID。

nextChar('yz'); // returns "ZA"

nextChar(yz);/ /返回“咱”

    function nextChar(c) {
        var u = c.toUpperCase();
        if (same(u,'Z')){
            var txt = '';
            var i = u.length;
            while (i--) {
                txt += 'A';
            }
            return (txt+'A');
        } else {
            var p = "";
            var q = "";
            if(u.length > 1){
                p = u.substring(0, u.length - 1);
                q = String.fromCharCode(p.slice(-1).charCodeAt(0));
            }
            var l = u.slice(-1).charCodeAt(0);
            var z = nextLetter(l);
            if(z==='A'){
                return p.slice(0,-1) + nextLetter(q.slice(-1).charCodeAt(0)) + z;
            } else {
                return p + z;
            }
        }
    }
    
    function nextLetter(l){
        if(l<90){
            return String.fromCharCode(l + 1);
        }
        else{
            return 'A';
        }
    }
    
    function same(str,char){
        var i = str.length;
        while (i--) {
            if (str[i]!==char){
                return false;
            }
        }
        return true;
    }

// below is simply for the html sample interface and is unrelated to the javascript solution

var btn = document.getElementById('btn');
var entry = document.getElementById('entry');
var node = document.createElement("div");
node.id = "node";

btn.addEventListener("click", function(){
  node.innerHTML = '';
  var textnode = document.createTextNode(nextChar(entry.value));
  node.appendChild(textnode);
  document.body.appendChild(node);
});

<input id="entry" type="text"></input>
<button id="btn">enter</button>

#4

You can try this

你可以试试这个

console.log( 'a'.charCodeAt(0))

First convert it to Ascii number .. Increment it .. then convert from Ascii to char..

首先把它转换成Ascii码。将它加. .然后从Ascii码转换为char。

var nex = 'a'.charCodeAt(0);
console.log(nex)
$('#btn1').on('click', function() {
   var curr = String.fromCharCode(nex++)
   console.log(curr)
});

Check FIDDLE

检查小提琴

#5

I needed to use sequences of letters multiple times and so I made this function based on this SO question. I hope this can help others.

我需要多次使用字母序列所以我基于这个so问题做了这个函数。我希望这能帮助别人。

function charLoop(from, to, callback)
{
    var i = from.charCodeAt(0);
    var to = to.charCodeAt(0);
    for(;i<=to;i++) callback(String.fromCharCode(i));
}

from - start letter
从- - -开始信
to - last letter
——最后一个字母
callback(letter) - function to execute for each letter in the sequence
回调(字母)-函数执行序列中的每个字母

How to use it:

如何使用它:

charLoop("A", "K", function(char) {
    //char is one letter of the sequence
});

See this working demo

看到这个演示工作

#6

Adding upon all these answers:

加上所有这些答案:

// first code on page
String.prototype.nextChar = function(i) {
    var n = i | 1;
    return String.fromCharCode(this.charCodeAt(0) + n);
}

String.prototype.prevChar = function(i) {
    var n = i | 1;
    return String.fromCharCode(this.charCodeAt(0) - n);
}

Example: http://jsfiddle.net/pitaj/3F5Qt/

例如:http://jsfiddle.net/pitaj/3F5Qt/

#7

This one does work well:

这个方法确实很有效:

var nextLetter = letter => {
    let charCode = letter.charCodeAt(0);
    let isCapital = letter == letter.toUpperCase();

    if (isCapital == true) {
        return String.fromCharCode((charCode - 64) % 26 + 65)
    } else {
        return String.fromCharCode((charCode - 96) % 26 + 97)
    }
}

EXAMPLES

nextLetter("a"); // returns 'b'
nextLetter("z"); // returns 'a'
nextLetter("A"); // returns 'B'
nextLetter("Z"); // returns 'A'

#8

This is really old. But I needed this functionality and none of the solutions are optimal for my use case. I wanted to generate a, b, c...z, aa,ab...zz, aaa... . This simple recursion does the job.

这真的是老了。但是我需要这个功能，没有一个解决方案适合我的用例。我想生成a b c…z,aa、ab……zz,aaa…。这个简单的递归就可以了。

function nextChar(str) {
if (str.length == 0) {
    return 'a';
}
var charA = str.split('');
if (charA[charA.length - 1] === 'z') {
    return nextID(str.substring(0, charA.length - 1)) + 'a';
} else {
    return str.substring(0, charA.length - 1) +
        String.fromCharCode(charA[charA.length - 1].charCodeAt(0) + 1);
}
};

#1

119

function nextChar(c) {
    return String.fromCharCode(c.charCodeAt(0) + 1);
}
nextChar('a');

#2