Instance Method

formRemainder(dividingBy:)

Replaces this value with the remainder of itself divided by the given value.

Declaration

mutating func formRemainder(dividingBy other: Double)

Parameters

other: The value to use when dividing this value.

Discussion

For two finite values x and y, the remainder r of dividing x by y satisfies x == y * q + r, where q is the integer nearest to x / y. If x / y is exactly halfway between two integers, q is chosen to be even. Note that q is not x / y computed in floating-point arithmetic, and that q may not be representable in any available integer type.

The following example calculates the remainder of dividing 8.625 by 0.75:

var x = 8.625
print(x / 0.75)
// Prints "11.5"

let q = (x / 0.75).rounded(.toNearestOrEven)
// q == 12.0
x.formRemainder(dividingBy: 0.75)
// x == -0.375

let x1 = 0.75 * q + x
// x1 == 8.625

If this value and other are finite numbers, the remainder is in the closed range -abs(other / 2)...abs(other / 2). The formRemainder(dividingBy:) method is always exact.

Relationships

From Protocol

FloatingPoint