JS multiplying by 100 giving wierd result [duplica

问题:

This question already has answers here:

Is floating point math broken? (29 answers)

Closed 6 years ago.

I have:

var a =  0.0532;
var b =  a * 100;

b should be returning 5.32 but instead it's returning 5.319999999999999. How do I fix this?

JSFiddle here: http://jsfiddle.net/9f2K8/

回答1:

you should use .toFixed()

FIDDLE

var a =  0.0532;
var b =  a * 100;
b.toFixed(2);     //specify number of decimals to be displayed

回答2:

This is not an error.

Very simply put, javascript is trying to represent 5.32 with as much precision as possible. Since computers don't have infinite precision, it picks the number that is closest: 5.319999999999999.

An error margin of 0.0000000000001 should be more than acceptable, no?

You can always round the number to less decimal digits, or use toFixed() to create a rounded string:

number = 123.4567
number.toFixed(2)
> '123.46'

回答3:

You can use ToFixed to round it back:

b = b.ToFixed(2);