How to xor my Strings using javascript

Question

Am trying to XOR Two Strings. It's returning value with exponential notation, but in my case i need to pad the unmatched string with 0's.

x1 = "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000";
x2 = "00000000000000000000000000000000011000000000000000000000000000000000000000000000000000000";
xor1 = parseInt(x1, 2);
xor2 = parseInt(x2, 2);
console.log(xor1, xor2);

Those numbers are too big for JavaScript to handle precisely. Consider using string functions instead. — Niet the Dark Absol, Nov 27 '16 at 14:04
Do it one character at a time and concatenate the result. Just write you own XOR for characters. Look at http://stackoverflow.com/questions/20566421/xor-of-two-hex-strings-in-javascript for some ideas. — PM 77-1, Nov 27 '16 at 14:07
what does this have to do with angularjs? Don't use a framework tag for a language question just because you use the framework in other parts of your app.... — Claies, Nov 27 '16 at 14:53

clinton3141 · Accepted Answer · 2016-11-27T18:56:29.293

In your code, you are parsing the string to binary numbers. parseInt("0001100", 2) is 0b001100, or 12 in decimal. The numbers you're attempting to parse are way larger than MAX_SAFE_INTEGER, but that's kind of irrelevant anyway...

It's not possible to add leading zeroes to a number using xor, since the leading numbers are implicitly there anyway, so it won't change the representation of the number:

(0b0000 ^ 0b100) === 0b100, so toString(2)-ing that will leave you with "100".

You'll need to go through your string character by character and build a string from it.

let x =    "11000000000000000000000000000000000000000000000000000000";
let mask = "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000";

let result = mask.split("").reduceRight(function(partialResult, value, index) {
  if (index < x.length && x.charAt(x.length - index - 1) === "1") {
    return partialResult + "1";
  } else {
    return partialResult + "0";
  }
}, "");

console.log("Result is: " + result);

How to xor my Strings using javascript

1 Answers1