(function(){
   var a = 10,b = 2;
   a = a + b;
   b = a - b;
   a = a - b;
   alert(a+" "+b);
})();
(function(){

var a = 10,b=2;

a = a^b;

b = b^a;

a = a ^b;

alert(a+" "+b);

})();
(function(){

var a =10,b =2 ;

a=[a,b];

b=a[0];

a=a[1];

alert(a+" "+b)

})();

//简化一下：

(function(){

var a =10,b =2 ;

a=[b,b=a][0];

alert(a+" "+b)

})();
(function(){

var a = 10,b = 2;

a = {a : b,b : a};

b = a.b;

a = a.a;

alert(a+" "+b);

})();
(function(){

var a = 10,b = 2;

a=(function(){

try {

return b;

}

finally {

b = a;

}

})();

alert(a+" "+b);

})();
(function(){

var a = 10,b = 2;

eval("a="+b+";b="+a);

alert(a+" "+b);

})();
(function(){

var a =10,b =2 ;

a = b+(b = a)*0;

alert(a+" "+b)

})(); 
(function(){

var a =10,b =2 ;

a = (a + b) - (b = a);

alert(a+" "+b)

})();