How do I round a double to certain decimals in KMM...

# multiplatform

[John Huang]

How do I round a double to certain decimals in KMM? For example:

0.6234.round(0.001, Round.down) should give 0.623
0.6234.round(0.001, Round.up) should give 0.624
0.6234.round(0.001, Round.nearest) should give 0.623

Ideally, it can round to 10's, 100's etc

6234.round(10, Round.down) should be 6230
6234.round(10, Round.up) should be 6240
6234.round(10, Round.nearest) should be 6230

[Håkon Pettersen]

We have created an extension-function for this:

internal fun Double.fractionDigits(fractionDigits: Int): Double {
    val factor = 10.0.pow(fractionDigits)
    return round(factor * this) / factor
}

[John Huang]

Will there be issues with double calculation inaccuracy? For example, I don't want 2.64.fractionDigits(1) to be like 2.60000000000001