Instance Method

rounded(_:)

Returns this value rounded to an integral value using the specified rounding rule.

Declaration

func rounded(_ rule: FloatingPointRoundingRule) -> Double

Parameters

rule

The rounding rule to use.

Return Value

The integral value found by rounding using rule.

Discussion

The following example rounds a value using four different rounding rules:

let x = 6.5

// Equivalent to the C 'round' function:
print(x.rounded(.toNearestOrAwayFromZero))
// Prints "7.0"

// Equivalent to the C 'trunc' function:
print(x.rounded(.towardZero))
// Prints "6.0"

// Equivalent to the C 'ceil' function:
print(x.rounded(.up))
// Prints "7.0"

// Equivalent to the C 'floor' function:
print(x.rounded(.down))
// Prints "6.0"

For more information about the available rounding rules, see the FloatingPointRoundingRule enumeration. To round a value using the default “schoolbook rounding”, you can use the shorter rounded() method instead.

print(x.rounded())
// Prints "7.0"

See Also

Rounding Values

func rounded() -> Double

Returns this value rounded to an integral value using “schoolbook rounding.”

func round()

Rounds this value to an integral value using “schoolbook rounding.”

func round(FloatingPointRoundingRule)

Rounds the value to an integral value using the specified rounding rule.