I would like to find a function that will return this kind of formatted values :
1.5555 => 1.55
1.5556 => 1.56
1.5554 => 1.55
1.5651 => 1.56
toFixed() and math round return this value :
1.5651.fixedTo(2) => 1.57
This will be usefull for money rounding.
I would like to find a function that will return this kind of formatted values :
1.5555 => 1.55
1.5556 => 1.56
1.5554 => 1.55
1.5651 => 1.56
toFixed() and math round return this value :
1.5651.fixedTo(2) => 1.57
This will be usefull for money rounding.
Share Improve this question edited Apr 4, 2011 at 8:31 mplungjan 178k28 gold badges181 silver badges240 bronze badges asked May 18, 2010 at 20:47 bdo334bdo334 4082 gold badges9 silver badges20 bronze badges 6- 1 You have the fourth decimal affect the second decimal? When ever would you use this? – Matti Virkkunen Commented May 18, 2010 at 20:50
- 6 Why would you want to round in such a strange way? How would this be useful for money rounding? – sth Commented May 18, 2010 at 20:55
- 1 Your examples don't really seem to be getting your point across. What's the rule you're trying to enforce, exactly? Round down on a final "5" digit, unless the next digit is > 5? – Mark Bessey Commented May 19, 2010 at 0:22
- Indeed, this is a strange way of rounding. Doesn't really make any sense to me. – Sasha Chedygov Commented May 19, 2010 at 0:51
- Isn't that how Richar Pryor made all that money in that Superman movie? – kennebec Commented May 19, 2010 at 1:33
3 Answers
Reset to default 6How about this?
function wacky_round(number, places) {
var multiplier = Math.pow(10, places+2); // get two extra digits
var fixed = Math.floor(number*multiplier); // convert to integer
fixed += 44; // round down on anything less than x.xxx56
fixed = Math.floor(fixed/100); // chop off last 2 digits
return fixed/Math.pow(10, places);
}
1.5554 => 1.55
1.5555 => 1.55
1.5556 => 1.56
1.5651 => 1.56
So, that works, but I think you'll find that it's not a generally-accepted way to round. http://en.wikipedia/wiki/Rounding#Tie-breaking
And standard function
fixedTo = function (number, n) {
var k = Math.pow(10, n);
return (Math.round(number * k) / k);
}
and then call
fixedTo(1.5555, 2) // 1.56
fixedTo(1.5555, 2) // 1.556
fixedTo(0.615, 2) // 0.62
You can use the native Number.toFixed() method.
parseFloat(10.159.toFixed(2))
The above returns 10.16. Number.toFixed() returns a string, so I use parseFloat to convert it to a number.