Need to escape non-ASCII characters in JavaScript

Question

Is there any function to do the following?

var specialStr = 'ipsum áá éé lore';
var encodedStr = someFunction(specialStr);
// then encodedStr should be like 'ipsum \u00E1\u00E1 \u00E9\u00E9 lore'

I need to encode the characters that are out of ASCII range, and need to do it with that encoding. I don't know its name. Is it Unicode maybe?

Answer 1

This should do the trick:

function padWithLeadingZeros(string) {
    return new Array(5 - string.length).join("0") + string;
}

function unicodeCharEscape(charCode) {
    return "\\u" + padWithLeadingZeros(charCode.toString(16));
}

function unicodeEscape(string) {
    return string.split("")
                 .map(function (char) {
                     var charCode = char.charCodeAt(0);
                     return charCode > 127 ? unicodeCharEscape(charCode) : char;
                 })
                 .join("");
}

For example:

var specialStr = 'ipsum áá éé lore';
var encodedStr = unicodeEscape(specialStr);

assert.equal("ipsum \\u00e1\\u00e1 \\u00e9\\u00e9 lore", encodedStr);

Answer 2

If you need hex encoding rather than unicode then you can simplify @Domenic's answer to:

"aäßåfu".replace(/./g, function(c){return c.charCodeAt(0)<128?c:"\\x"+c.charCodeAt(0).toString(16)})

returns: "a\xe4\xdf\xe5fu"