Swift Tutorial Swift References

Swift - asin() Function

The Swift asin() function returns arc sine of a value. The return value will be in the range -𝜋/2 through 𝜋/2.


In Foundation framework, it is defined as follows:

public func asin(_ x: CGFloat) -> CGFloat
public func asin(_ x: Float) -> Float
public func asin(_ x: Float80) -> Float80
public func asin(_ __x: Double) -> Double


x Specify the value in range [-1.0, 1.0].

Return Value

Returns the arc sine of the value.
If the x is not in the range of [-1.0, 1.0], it returns nan.


In the example below, asin() function is used to is used to find out the arc sine of a given value.

import Foundation

print("asin(0.0) = \(asin(0.0))")
print("asin(0.5) = \(asin(0.5))")
print("asin(1.0) = \(asin(1.0))")
print("asin(2.0) = \(asin(2.0))")

The output of the above code will be:

asin(0.0) = 0.0
asin(0.5) = 0.5235987755982989
asin(1.0) = 1.5707963267948966
asin(2.0) = nan

❮ Swift Math Functions