round to nearest .25 javascript

Question

I want to convert all numbers to the nearest .25

So...

5 becomes 5.00
2.25 becomes 2.25
4 becomes 4.00
3.5 becomes 3.50

Thanks

Answer 1

Here is a generic function to do rounding. In the examples above, 4 was used because that is in the inverse of .25. This function allows the user to ignore that detail. It doesn't currently support preset precision, but that can easily be added.

function roundToNearest(numToRound, numToRoundTo) {
    numToRoundTo = 1 / (numToRoundTo);

    return Math.round(numToRound * numToRoundTo) / numToRoundTo;
}

Answer 2

function roundToInc(num, inc) {
    const diff = num % inc;
    return diff>inc/2?(num-diff+inc):num-diff;
}

> roundToInc(233223.2342343, 0.01)
233223.23
> roundToInc(505, 5)
505
> roundToInc(507, 5)
505
> roundToInc(508, 5)
510