为什么我在ECMAScript/ActionScript 3中看到不精确的浮点结果?

大家好,让我们直接跳到一个代码示例,展示ECMAScript/JavaScript/AS3如何不能正确地进行简单的数学运算(AS3对数字类使用了“IEEE-754双精度浮点数字”,该数字类应该与JavaScript中使用的数字相同)。。。

trace(1.1);         //'1.1': Ok, fine, looks good.
trace(1.1*100);     //'110.00000000000001': What!?
trace((1.1*100)/100);  //'1.1': Brings it back to 1.1 (since we're apparently multiplying by *approximately* 100 and then dividing by the same *approximate* '100' amount)
trace(1.1*100-110); //'1.4210854715202004e-14': Proof that according to AS3, 1.1*100!=110 (i.e. this isn't just a bug in Number.toString())
trace(1.1*100==110);   //'false': Even further proof that according to AS3, 1.1*100!=110

有什么好处?