round value to 2 decimals javascript

问题

I have a small issue with the final value, i need to round to 2 decimals.

var pri='#price'+$(this).attr('id').substr(len-2);
            $.get("sale/price?output=json", { code: v },
               function(data){
                 $(pri).val(Math.round((data / 1.19),2));
            });
        });

Any help is appreciated.

Solution: $(pri).val(Math.round((data / 1.19 * 100 )) / 100);

回答1:

Just multiply the number by 100, round, and divide the resulting number by 100.

回答2:

If you want it visually formatted to two decimals as a string (for output) use toFixed():

var priceString = someValue.toFixed(2);

The answer by @David has two problems:

1. It leaves the result as a floating point number, and consequently holds the possibility of displaying a particular result with many decimal places, e.g. 134.1999999999 instead of "134.20".

2. If your value is an integer or rounds to one tenth, you will not see the additional decimal value:

   var n = 1.099;
   (Math.round( n * 100 )/100 ).toString() //-> "1.1"
   n.toFixed(2)                            //-> "1.10"
   
   var n = 3;
   (Math.round( n * 100 )/100 ).toString() //-> "3"
   n.toFixed(2)                            //-> "3.00"
   

And, as you can see above, using toFixed() is also far easier to type. ;)

来源：https://stackoverflow.com/questions/14666752/round-value-to-2-decimals-javascript