Convert character to ASCII code in JavaScript

Convert character to ASCII code in JavaScript

How can I convert a character to its ASCII code using JavaScript?
For example:

get 10 from “\n”.

Solutions/Answers:

Solution 1:

"\n".charCodeAt(0);

Solution 2:

String.prototype.charCodeAt() can convert string characters to ASCII numbers. For example:

"ABC".charCodeAt(0) // returns 65

For opposite use String.fromCharCode(10) that convert numbers to equal ASCII character. This function can accept multiple numbers and join all the characters then return the string. Example:

String.fromCharCode(65,66,67); // returns 'ABC'

Here is a quick ASCII characters reference:

{
"31": "",      "32": " ",     "33": "!",     "34": "\"",    "35": "#",    
"36": "$",     "37": "%",     "38": "&",     "39": "'",     "40": "(",    
"41": ")",     "42": "*",     "43": "+",     "44": ",",     "45": "-",    
"46": ".",     "47": "/",     "48": "0",     "49": "1",     "50": "2",    
"51": "3",     "52": "4",     "53": "5",     "54": "6",     "55": "7",    
"56": "8",     "57": "9",     "58": ":",     "59": ";",     "60": "<",    
"61": "=",     "62": ">",     "63": "?",     "64": "@",     "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",    
"91": "[",     "92": "\\",    "93": "]",     "94": "^",     "95": "_",    
"96": "`",     "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",    "123": "{",    "124": "|",    "125": "}",    
"126": "~",    "127": ""
}

Solution 3:

If you have only one char and not a string, you can use:

'\n'.charCodeAt();

omitting the 0…

It is slower though. With the current version of chrome, it is 5 times slower.

Solution 4:

While the other answers are right, I prefer this way:

function ascii (a) { return a.charCodeAt(0); }

Then, to use it, simply:

var lineBreak = ascii("\n");

I am using this for a small shortcut system:

$(window).keypress(function(event) {
  if (event.ctrlKey && event.which == ascii("s")) {
    savecontent();
    }
  // ...
  });

And you can even use it inside map() or other methods:

var ints = 'ergtrer'.split('').map(ascii);

Solution 5:

For those that want to get a sum of all the ASCII codes for a string:

'Foobar'
  .split('')
  .map(function (char) {
    return char.charCodeAt(0);
  })
  .reduce(function (current, previous) {
    return previous + current;
  });

Or, ES6:

[...'Foobar']
  .map(char => char.charCodeAt(0))
  .reduce((current, previous) => previous + current)

Solution 6:

JavaScript stores strings as UTF-16 (double byte) so if you want to ignore the second byte just strip it out with a bitwise & operator on 0000000011111111 (ie 255):

'a'.charCodeAt(0) & 255 === 97; // because 'a' = 97 0 
'b'.charCodeAt(0) & 255 === 98; // because 'b' = 98 0 
'✓'.charCodeAt(0) & 255 === 19; // because '✓' = 19 39