Zach’s ugly mug (his face) Zach Leat­herman

Logical XOR in JavaScript

March 23, 2007

Of course there wouldn’t be an XOR function in JavaScript when I needed one. So I googled around and found an implementation at How To Create. But it only took two arguments. So I rolled my own supporting a variable number of arguments. In my personal stuff, I’ve put it into a Math library under the YAHOO namespace, and you can decide if you want to do that on your own.

function xor() {
  var b = false;
  for( var j = 0; j < arguments.length; j++ ) {
    if( arguments[ j ] && !b ) b = true;
    else if( arguments[ j ] && b ) return false;
  }

  return b;
};

Usage:

xor( false, true ); // true
xor( true, true ); // false
xor( false, false, true, true, true, false, true, false ); // false
xor( false, false, false, true, false, false, false, false ); // true

Zach Leatherman is a builder for the web at Font Awesome and the creator of Build Awesome (née Eleventy/11ty), an award-winning open source website generator. He measures website performance with speedlify and at one point became too fixated on web fonts. He has given 86 talks in nine different countries at events like Beyond Tellerrand, Smashing Conference, Jamstack Conf, CSSConf, and The White House. Learn more about Zach »