Array.prototype.valueOf = function ():Number
{
var sum:Number = 0;
for each (var v:* in this)
{
if (v is Number)
{
sum += v;
}
}
return sum;
};
trace( [1,2,3, 7] + [3,2,1] + [5,3,2] ); // Yeah! 29 output
转自
http://filimanjaro.com/2012/operators-overloading-in-as3-javascript-too-%E2%80%93-workaround/