Structure

Double

A double-precision, floating-point value type.

Topics

Converting Integers

init<Source>(Source)

Creates a new value, rounded to the closest possible representation.

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init(Int)

Creates the closest representable value to the given integer.

init(Int8)

Creates the closest representable value to the given integer.

init(Int16)

Creates the closest representable value to the given integer.

init(Int32)

Creates the closest representable value to the given integer.

init(Int64)

Creates the closest representable value to the given integer.

init(UInt)

Creates the closest representable value to the given integer.

init(UInt8)

Creates the closest representable value to the given integer.

init(UInt16)

Creates the closest representable value to the given integer.

init(UInt32)

Creates the closest representable value to the given integer.

init(UInt64)

Creates the closest representable value to the given integer.

Converting Strings

init?<S>(S)

Creates a new instance from the given string.

Converting Floating-Point Values

init<Source>(Source)

Creates a new instance from the given value, rounded to the closest possible representation.

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init(Double)

Creates a new instance initialized to the given value.

init(Float)

Creates a new instance that approximates the given value.

init(Float80)

Creates a new instance that approximates the given value.

init(CGFloat)

Creates a new instance initialized to the given value.

init(truncating: NSNumber)

Creates a new instance that approximates the given value.

init(NSNumber)

Creates a new instance that approximates the given value.

Deprecated
init(sign: FloatingPointSign, exponent: Int, significand: Double)

Creates a new value from the given sign, exponent, and significand.

init(signOf: Double, magnitudeOf: Double)

Creates a new floating-point value using the sign of one value and the magnitude of another.

Converting Exactly

These initializers result in nil if the value passed can't be represented without any loss of precision.

init?<Source>(exactly: Source)

Creates a new value, if the given integer can be represented exactly.

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init?<Source>(exactly: Source)

Creates a new instance from the given value, if it can be represented exactly.

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init?(exactly: Double)

Creates a new instance initialized to the given value, if it can be represented without rounding.

init?(exactly: Float)

Creates a new instance initialized to the given value, if it can be represented without rounding.

init?(exactly: Float80)

Creates a new instance initialized to the given value, if it can be represented without rounding.

init?(exactly: NSNumber)

Creates a new instance initialized to the given value, if it can be represented without rounding.

init?(exactly: Int)

Creates a value that exactly represents the given integer.

init?(exactly: Int16)

Creates a value that exactly represents the given integer.

init?(exactly: Int8)

Creates a value that exactly represents the given integer.

init?(exactly: Int32)

Creates a value that exactly represents the given integer.

init?(exactly: Int64)

Creates a value that exactly represents the given integer.

init?(exactly: UInt)

Creates a value that exactly represents the given integer.

init?(exactly: UInt8)

Creates a value that exactly represents the given integer.

init?(exactly: UInt16)

Creates a value that exactly represents the given integer.

init?(exactly: UInt32)

Creates a value that exactly represents the given integer.

init?(exactly: UInt64)

Creates a value that exactly represents the given integer.

Creating a Random Value

static func random(in: Range<Double>) -> Double

Returns a random value within the specified range.

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static func random(in: ClosedRange<Double>) -> Double

Returns a random value within the specified range.

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Performing Calculations

Floating-Point Operators for Double

Perform arithmetic and bitwise operations or compare values.

func addingProduct(Double, Double) -> Double

Returns the result of adding the product of the two given values to this value, computed without intermediate rounding.

func addProduct(Double, Double)

Adds the product of the two given values to this value in place, computed without intermediate rounding.

func squareRoot() -> Double

Returns the square root of the value, rounded to a representable value.

func formSquareRoot()

Replaces this value with its square root, rounded to a representable value.

func remainder(dividingBy: Double) -> Double

Returns the remainder of this value divided by the given value.

func formRemainder(dividingBy: Double)

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

func truncatingRemainder(dividingBy: Double) -> Double

Returns the remainder of this value divided by the given value using truncating division.

func formTruncatingRemainder(dividingBy: Double)

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

func negate()

Replaces this value with its additive inverse.

func negate()

Replaces this value with its additive inverse.

Rounding

func rounded() -> Double

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

func rounded(FloatingPointRoundingRule) -> Double

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

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.

Comparing Doubles

Floating-Point Operators for Double

Perform arithmetic and bitwise operations or compare values.

func isEqual(to: Double) -> Bool

Returns a Boolean value indicating whether this instance is equal to the given value.

func isLess(than: Double) -> Bool

Returns a Boolean value indicating whether this instance is less than the given value.

func isLessThanOrEqualTo(Double) -> Bool

Returns a Boolean value indicating whether this instance is less than or equal to the given value.

func isTotallyOrdered(belowOrEqualTo: Double) -> Bool

Returns a Boolean value indicating whether this instance should precede or tie positions with the given value in an ascending sort.

static func minimum(Double, Double) -> Double

Returns the lesser of the two given values.

static func minimumMagnitude(Double, Double) -> Double

Returns the value with lesser magnitude.

static func maximum(Double, Double) -> Double

Returns the greater of the two given values.

static func maximumMagnitude(Double, Double) -> Double

Returns the value with greater magnitude.

Finding the Sign and Magnitude

var magnitude: Double

The magnitude of this value.

var sign: FloatingPointSign

The sign of the floating-point value.

Querying a Double

var ulp: Double

The unit in the last place of this value.

var significand: Double

The significand of the floating-point value.

var exponent: Int

The exponent of the floating-point value.

var nextUp: Double

The least representable value that compares greater than this value.

var nextDown: Double

The greatest representable value that compares less than this value.

var binade: Double

The floating-point value with the same sign and exponent as this value, but with a significand of 1.0.

Accessing Numeric Constants

static var pi: Double

The mathematical constant pi.

static var infinity: Double

Positive infinity.

static var greatestFiniteMagnitude: Double

The greatest finite number representable by this type.

static var nan: Double

A quiet NaN (“not a number”).

static var signalingNaN: Double

A signaling NaN (“not a number”).

static var ulpOfOne: Double

The unit in the last place of 1.0.

static var ulpOfOne: Double

The unit in the last place of 1.0.

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static var leastNormalMagnitude: Double

The least positive normal number.

Working with Binary Representation

var bitPattern: UInt64

The bit pattern of the value’s encoding.

var significandBitPattern: UInt64

The raw encoding of the value’s significand field.

var significandWidth: Int

The number of bits required to represent the value’s significand.

var exponentBitPattern: UInt

The raw encoding of the value’s exponent field.

static var significandBitCount: Int

The available number of fractional significand bits.

static var exponentBitCount: Int

The number of bits used to represent the type’s exponent.

static var radix: Int

The radix, or base of exponentiation, for this floating-point type.

init(bitPattern: UInt64)

Creates a new value with the given bit pattern.

init(sign: FloatingPointSign, exponentBitPattern: UInt, significandBitPattern: UInt64)

Creates a new instance from the specified sign and bit patterns.

init(nan: Double.RawSignificand, signaling: Bool)

Creates a NaN (“not a number”) value with the specified payload.

Querying a Double's State

var isZero: Bool

A Boolean value indicating whether the instance is equal to zero.

var isFinite: Bool

A Boolean value indicating whether this instance is finite.

var isInfinite: Bool

A Boolean value indicating whether the instance is infinite.

var isNaN: Bool

A Boolean value indicating whether the instance is NaN (“not a number”).

var isSignalingNaN: Bool

A Boolean value indicating whether the instance is a signaling NaN.

var isNormal: Bool

A Boolean value indicating whether this instance is normal.

var isSubnormal: Bool

A Boolean value indicating whether the instance is subnormal.

var isCanonical: Bool

A Boolean value indicating whether the instance’s representation is in the canonical form.

Encoding and Decoding

func encode(to: Encoder)

Encodes this value into the given encoder.

init(from: Decoder)

Creates a new instance by decoding from the given decoder.

Creating a Range

static func ..< (Double, Double) -> Range<Double>

Returns a half-open range that contains its lower bound but not its upper bound.

static func ... (Double, Double) -> ClosedRange<Double>

Returns a closed range that contains both of its bounds.

Describing a Double

var description: String

A textual representation of the value.

var debugDescription: String

A textual representation of the value, suitable for debugging.

var customMirror: Mirror

A mirror that reflects the Double instance.

var customPlaygroundQuickLook: PlaygroundQuickLook

A custom playground Quick Look for the Double instance.

Deprecated
func hash(into: inout Hasher)

Hashes the essential components of this value by feeding them into the given hasher.

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Type Aliases

typealias Double.Exponent

A type that can represent any written exponent.

typealias Double.Magnitude

A type that can represent the absolute value of any possible value of this type.

typealias Double.RawSignificand

A type that represents the encoded significand of a value.

Infrequently Used Functionality

init()

Creates a value initialized to zero.

init(floatLiteral: Double)

Creates a new value from the given floating-point literal.

init(integerLiteral: Int64)

Creates a new value from the given integer literal.

init(integerLiteral: Double)

Creates an instance initialized to the specified integer value.

func advanced(by: Double) -> Double

Returns a new value advanced by the given distance.

func distance(to: Double) -> Double

Returns the distance from this value to the specified value.

Type Methods

static func random<T>(in: ClosedRange<Double>, using: inout T) -> Double

Returns a random value within the specified range, using the given generator as a source for randomness.

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static func random<T>(in: Range<Double>, using: inout T) -> Double

Returns a random value within the specified range, using the given generator as a source for randomness.

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Operator Functions

static func < (Double, Double) -> Bool

Returns a Boolean value indicating whether the value of the first argument is less than that of the second argument.

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static func < (Double, Double) -> Bool

Returns a Boolean value indicating whether the value of the first argument is less than that of the second argument.

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static func <= (Double, Double) -> Bool

Returns a Boolean value indicating whether the value of the first argument is less than or equal to that of the second argument.

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static func <= (Double, Double) -> Bool

Returns a Boolean value indicating whether the value of the first argument is less than or equal to that of the second argument.

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static func == (Double, Double) -> Bool

Returns a Boolean value indicating whether two values are equal.

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static func == (Double, Double) -> Bool

Returns a Boolean value indicating whether two values are equal.

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static func > (Double, Double) -> Bool

Returns a Boolean value indicating whether the value of the first argument is greater than that of the second argument.

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static func > (Double, Double) -> Bool

Returns a Boolean value indicating whether the value of the first argument is greater than that of the second argument.

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static func >= (Double, Double) -> Bool

Returns a Boolean value indicating whether the value of the first argument is greater than or equal to that of the second argument.

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static func >= (Double, Double) -> Bool

Returns a Boolean value indicating whether the value of the first argument is greater than or equal to that of the second argument.

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See Also

Standard Library

struct Int

A signed integer value type.

struct String

A Unicode string value that is a collection of characters.

struct Array

An ordered, random-access collection.

struct Dictionary

A collection whose elements are key-value pairs.

Swift Standard Library

Solve complex problems and write high-performance, readable code.

Beta Software

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