gistfile1.js

// If you want to flip a variable from true to false, you can do the following:

var x = false;
x = !!(x-1);

// At this point, x is true.

// Let's say you want to flip 0 to 1 or 1 to 0:

var y = 1;
y = -y+1;

// At this point, y is 0.

gistfile2.js

// Also to convert boolean to int real fast.
var y = false;
y = +y;

// y = 0

// Reference: http://www.jibbering.com/faq/faq_notes/type_convert.html#tcNumber