[solved]Why Number function sometimes gets some unpredictable real parts?

[owenzhao]

I am using javascript Number function to convert string to real from textField.text. I have made to textField.text can only accept number like 80.3 which mean only have 1 decimal from the decimal point.

However, I find sometimes the conversion is not always what I want. For example, when I input 80.2 in the textField, the conversion is 80.2. However, when I input 88.7, I will get 88.69999694824219.

So I have to use Math.round() to deal with what Number() gets.

My question is, is that Number() are always not trustable that we should always use a round() dealing with it? I also want to know why this happened?

[owenzhao]

I find this. http://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html =.=||

[mlong]

That is a good reference. Thanks for the link!