[javascript] How to round up a number in Javascript?

The OP expects two things:
A. to round up to the higher tenths, and
B. to show a zero in the hundredths place (a typical need with currency).

Meeting both requirement would seem to necessitate a separate method for each of the above. Here's an approach that builds on suryakiran's suggested answer:

//Arguments: number to round, number of decimal places.

function roundPrice(rnum, rlength) {
    var newnumber = Math.ceil(rnum * Math.pow(10, rlength-1)) / Math.pow(10, rlength-1);
    var toTenths = newnumber.toFixed(rlength);
    return toTenths;
}

alert(roundPrice(678.91011,2)); // returns 679.00
alert(roundPrice(876.54321,2)); // returns 876.60

Important note: this solution produces a very different result with negative and exponential numbers.

For the sake of comparison between this answer and two that are very similar, see the following 2 approaches. The first simply rounds to the nearest hundredth per usual, and the second simply rounds up to the nearest hundredth (larger).

function roundNumber(rnum, rlength) { 
    var newnumber = Math.round(rnum * Math.pow(10, rlength)) / Math.pow(10, rlength);
    return newnumber;
}

alert(roundNumber(678.91011,2)); // returns 678.91

function ceilNumber(rnum, rlength) { 
    var newnumber = Math.ceil(rnum * Math.pow(10, rlength)) / Math.pow(10, rlength);
    return newnumber;
}

alert(ceilNumber(678.91011,2)); // returns 678.92