Swiftに限らずだけど型変換はよく忘れるので備忘録
Int
Int -> String
let intNum : Int = 17
let stringNum : String = String(intNum)
print(stringNum) // 17
Int -> Double
let intNum : Int = 17
let doubleNum: Double = Double(intNum)
print(doubleNum) // 17.0
Int -> Float
let intNum : Int = 17
let floatNum: Float = Float(intNum)
print(floatNum) // 17.0
Float
Float -> String
let floatNum : Float = 17.5
let stringNum : String = String(floatNum)
print(stringNum) // 17.5
Float -> Int (小数点切り捨て)
let floatNum : Float = 17.5
let intNum : Int = Int(floatNum)
print(intNum) // 17
Float -> Double
let floatNum : Float = 17.5
let doubleNum : Double = Double(floatNum)
print(doubleNum) // 17.5
Double
Double -> String
let doubleNum: Double = 17.5
let stringNum : String = String(doubleNum)
print(stringNum) // 17.5
Double -> Int (小数点切り捨て)
let doubleNum : Double = 17.5
let intNum : Int = Int(doubleNum)
print(intNum) // 17
Double -> Float
let doubleNum : Double = 17.5
let floatNum : Float = Float(doubleNum)
print(floatNum) // 17.5
String
String -> Int(整数以外を指定した場合はnil)
let stringNum : String = "17"
let intNum : Int = Int(stringNum)
print(intNum) // 17
let stringNum : String = "17.5"
let intNum : Int? = Int(stringNum)
print(intNum) // nil
String -> Double(String -> Double変換はatof使う方法も)
let stringNum : String = "10.59"
let doubleNum : Double = Double(stringNum)!
print(doubleNum) // 10.59
import Darwin
let stringNum : String = "10.59"
let doubleNum : Double = atof(stringNum)
print(doubleNum) // 10.59
String -> Float
let stringNum : String = "17.5"
let floatNum : Float = Float(stringNum)
print(floatNum) // 17.5
Bool
Bool -> String
let bool : Bool = true
let stringBool : String = String(bool)
print(stringBool) // true
Bool -> Int
let bool : Bool = true
let intBool : Int = Int(bool)
print(intBool) // 1
Bool -> Float
let bool : Bool = true
let floatBool : Float = Float(bool)
print(floatBool) // 1.0
Bool -> Double
let bool : Bool = true
let doubleBool : Double = Double(bool)
print(doubleBool) // 1.0