JavaScript HEX encoding

hex.js

function toHex(s) {
    // utf8 to latin1
    var s = unescape(encodeURIComponent(s))
    var h = ''
    for (var i = 0; i < s.length; i++) {
        h += s.charCodeAt(i).toString(16)
    }
    return h
}

function fromHex(h) {
    var s = ''
    for (var i = 0; i < h.length; i+=2) {
        s += String.fromCharCode(parseInt(h.substr(i, 2), 16))
    }
    return decodeURIComponent(escape(s))
}

A better way is to use %20 format, like that:

function toHex(s) {
    let h = ''
    for (let i = s.length - 1; i >= 0; i--)
        h = '%'+ s.charCodeAt(i).toString(16) + h
    return h
}

toHex('test') // "%74%65%73%74"
decodeURIComponent('%74%65%73%74') // test

You are a life saver. I just needed to tweak your code to get what I have been looking for since 5 hours.
I needed to get 00480065006c006c006f instead of 48656c6c6f by converting the word Hello to utf-16
Thank you again

I wonder why nobody has made a @tc39 proposal to standardize and include this in JS. It's funny that JS has atob & btoa but hex processing can only be done on Numbers in vanilla JS.

Edit: atob and btoa aren't part of ES, so they don't count

> h = 'hello 🤣';
'hello 🤣'
> const encoded = Buffer.from(h).toString('hex');
undefined
> encoded
'68656c6c6f20f09fa4a3'
> Buffer.from(encoded, 'hex').toString();
'hello 🤣'
> 

@MGF15 that's only possible in NodeJS, this Gist is portable

Actually, this Gist is also not portable between environments. My bad