Try using toFixed function on value.
example is below:
var value = parseFloat(2.185);
var fixed = value.toFixed(2);
alert(fixed);
I tried and it worked well.
EDIT: You can always transform string to number using parseFloat(stringVar).
EDIT2:
function myRound(num, places) {
return parseFloat(num.toFixed(places));
}
EDIT 3:
Updated answer, tested and working:
function myRound(num, places) {
if (places== undefined) {
places = 2;
}
var mult = Math.pow(10,places + 1);
var mult2 = Math.pow(10,places);
return Math.round(num* mult / 10) / mult2;
}
EDIT 4:
Tested on most examples noted in comments:
function myRound(num, places) {
if (places== undefined) {
places = 2;
}
var mult = Math.pow(10,places);
var val = num* mult;
var intVal = parseInt(val);
var floatVal = parseFloat(val);
if (intVal < floatVal) {
val += 0.1;
}
return Math.round(val) / mult;
}
EDIT 5:
Only solution that I managed to find is to use strings to get round on exact decimal.
Solution is pasted below, with String prototype extension method, replaceAt.
Please check and let me know if anyone finds some example that is not working.
function myRound2(num, places) {
var retVal = null;
if (places == undefined) {
places = 2;
}
var splits = num.split('.');
if (splits && splits.length <= 2) {
var wholePart = splits[0];
var decimalPart = null;
if (splits.length > 1) {
decimalPart = splits[1];
}
if (decimalPart && decimalPart.length > places) {
var roundingDigit = parseInt(decimalPart[places]);
var previousDigit = parseInt(decimalPart[places - 1]);
var increment = (roundingDigit < 5) ? 0 : 1;
previousDigit = previousDigit + increment;
decimalPart = decimalPart.replaceAt(places - 1, previousDigit + '').substr(0, places);
}
retVal = parseFloat(wholePart + '.' + decimalPart);
}
return retVal;
}
String.prototype.replaceAt = function (index, character) {
return this.substr(0, index) + character + this.substr(index + character.length);
}