Round a float to the nearest multiple of ?

Question

How do I round a float value to the nearest multiple of \"n\"?

For instance, rounding 21.673 to the nearest multiple of 8 should result in 24.

And, rounding 21.6

Answer 1

It is easy

Math.round(value / n) * n

Answer 2

There's another one, slightly shorter, slightly faster:

const nearrestMultipleOfN = (N,n) => n*(N/n+0.5|0);

It seems to deliver what's expected:

const nearrestMultipleOfN = (N,n) => n*(N/n+0.5|0);
 
 console.log(nearrestMultipleOfN(21.673,8));
 console.log(nearrestMultipleOfN(21.673,4));

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If you find yourself looking for the greatest integer divisible by n that does not exceed N (i.e. return 6, divisible by 3, when given 8), you might go, like:

const nearrestMultipleOfN = (N,n) => n*(N/n|0);