swapping of two numbers in javascript without third variable.
var a = 10;
var b = 20;
document.write(""Before Swapping");
document.write(""a = "+a);
document.write(""b = "+b);
b = [a,a=b][0];
document.write(""After Swapping");
document.write(""a = "+a);
document.write(""b = "+b);