I wanted to make this Encoding/Decoding Javascript function, which I used to make in Java, but I haven't figured out how to cast bytes to a different types. Simply, I want to make this, but in Javascript :

(Java)
String input = "something", mssg;
int key = 12;
for(int i = 0; i < input.length(); i++) {
   mssg = mssg + (char) (input.charAt(i) ^ key);
}
return mssg;

See the (char) there? I have no idea how to do that in Javascript. To encode a character, or in Javascript's case, a Symbol, using the XOR operation with number 'key' to XOR the bytes of the symbol and then make a String out of it, which you can, by XORing the String by the same key, decode. Thanks for any help.