Question

Hey everyone quick question, I know this sounds strange to do in javascript but i have good use for it. I need to be able to parse a string passed in a textarea in such a way that escaped hex literals “\x41” or whatever are processed not as four chars ‘\’ ‘x’ ‘4’ ‘1’ but as ‘A’ for example:

var anA = "\x41";
console.log(anA); //emits "A"
var stringToParse = $(#someTextArea).val(); //using jquery for ease not a req
//lets say that "someTextArea" contains "\x41"
console.log(stringToParse); // equals "\" "x" "4" "1" -- not what i want
console.log(new String(stringToParse)); same as last
console.log(""+stringToParse); still doesnt work
console.log(stringToParse.toString()); failz all over (same result)

I want to be able to have a way for stringToParse to contain “A” not “\x41″… any ideas beyond regex? I’ll take a regex i guess, i just wanted a way to make javascript do my bidding 🙂

Answer 1

String.prototype.parseHex = function(){
    return this.replace(/\\x([a-fA-F0-9]{2})/g, function(a,b){
        return String.fromCharCode(parseInt(b,16));
    });
};

and in practice:

var v = $('#foo').val();
console.log(v);
console.log(v.parseHex());