HtmlEncode and HtmlDecode in Javascript

HtmlEncodeDecode.js

/* source: https://stackoverflow.com/a/7124052/2753545 */

function htmlEscape(str) {
    return str
        .replace(/&/g, '&')
        .replace(/"/g, '"')
        .replace(/'/g, ''')
        .replace(/</g, '&lt;')
        .replace(/>/g, '&gt;')
        .replace(/\//g, '&#x2F;');
}

// I needed the opposite function today, so adding here too:
function htmlUnescape(str){
    return str
        .replace(/&quot;/g, '"')
        .replace(/&#39;/g, "'")
        .replace(/&lt;/g, '<')
        .replace(/&gt;/g, '>')
        .replace(/&amp;/g, '&')
        .replace(/&#x2F;//g, '\\');
}