不使用中间变量，交换int型的 a, b两个变量的值

(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)})();

?