JavaScript - convert integer number to letter

console.log( String.fromCharCode(97) );  // a

console.log( String.fromCharCode(98) );  // b

console.log( String.fromCharCode(122) ); // z

​

console.log( String.fromCharCode(65) );  // A

console.log( String.fromCharCode(66) );  // B

console.log( String.fromCharCode(90) );  // Z

for (var i = 0; i < 26; ++i) {

    var code = i + 97;

    var letter = String.fromCharCode(code);

    console.log(code + ' : ' + letter);

}

for (var i = 0; i < 26; ++i) {

    var code = i + 65;

    var letter = String.fromCharCode(code);

    console.log(code + ' : ' + letter);

}

var alphabet = ''

    + 'abcdefghijklmnopqrstuvwxyz' 

    + 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';

​

for (var i = 0; i < alphabet.length; ++i) {

    var code = i;

​

    var letter = alphabet[code];

    //var letter = alphabet.charAt(code);

    console.log(code + ' : ' + letter);

}

var alphabet = {

     "65": "A",  "66": "B",  "67": "C",  "68": "D",  "69": "E", 

     "70": "F",  "71": "G",  "72": "H",  "73": "I",  "74": "J", 

     "75": "K",  "76": "L",  "77": "M",  "78": "N",  "79": "O", 

     "80": "P",  "81": "Q",  "82": "R",  "83": "S",  "84": "T", 

     "85": "U",  "86": "V",  "87": "W",  "88": "X",  "89": "Y", 

     "90": "Z",

​

     "97": "a",  "98": "b",  "99": "c", "100": "d", "101": "e", 

    "102": "f", "103": "g", "104": "h", "105": "i", "106": "j", 

    "107": "k", "108": "l", "109": "m", "110": "n", "111": "o", 

    "112": "p", "113": "q", "114": "r", "115": "s", "116": "t", 

    "117": "u", "118": "v", "119": "w", "120": "x", "121": "y", 

    "122": "z"

};

​

for (var i = 0; i < 128; ++i) {

    var code = i.toString();

​

    if (code in alphabet) {

        var letter = alphabet[code];

        console.log(code + ' : ' + letter);

    }

}