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swift 2.2基本数据类型详解

2016-12-21 17:28 281 查看
整数

1.分为有符号整数和无符号整数;

2.有符号: Int8 Int16 Int32 Int64 Int;

3.无符号: UInt8 UInt16 UInt32 UInt64 UInt。

整数类型区别

1.在内存占用空间不同(sizeof(Type)获取);

2.表达的数据范围不同(可用min,max属性获取)。

Tips

1.特殊整数类型Int,长度与当前平台原生字长一致;

2.32位机,sizeof(Int)等于sizeof(Int32);

3.64位机,sizeof(Int)等于sizeof(Int64);

4.UInt类似;

5.习惯在一般情况下使用Int,来提高代码一致性和可复用性。

浮点数

1.Float 32位浮点数;

2.Double 64位浮点数。



布尔值

Bool(true false)

其他

1.类型转换;

2.类型别名;

3.类型安全。

swift是类型安全的语言,在编译时进行类型检查。

代码实例

//: Playground - noun: a place where people can play

import UIKit

//: 声明整数并观察类型推倒结果

let intVal = 1

intVal.dynamicType

let int8Val : Int8 = 1

let int16Val : Int16 = 1

let int32Val : Int32 = 1

let int64Val : Int64 = 1

let intVal1 : Int = 1

print("Int8 \t size: \(sizeof(Int8)) \t min: \(Int8.min) \t\t\t\t\t max: \(Int8.max)")

print("Int16 \t size: \(sizeof(Int16)) \t min: \(Int16.min) \t\t\t\t max: \(Int16.max)")

print("Int32 \t size: \(sizeof(Int32)) \t min: \(Int32.min) \t\t\t max: \(Int32.max)")

print("Int64 \t size: \(sizeof(Int64)) \t min: \(Int64.min) max: \(Int64.max)")

print("Int \t size: \(sizeof(Int)) \t min: \(Int.min) \t max: \(Int.max)")

var uint8Val : UInt8 = 1

var uint16Val : UInt16 = 1

var uint32Val : UInt32 = 1

var uint64Val : UInt64 = 1

print("UInt8 \t size: \(sizeof(UInt8)) \t min: \(UInt8.min) \t max: \(UInt8.max)")

print("UInt16 \t size: \(sizeof(UInt16)) \t min: \(UInt16.min) \t max: \(UInt16.max)")

print("UInt32 \t size: \(sizeof(UInt32)) \t min: \(UInt32.min) \t max: \(UInt32.max)")

print("UInt64 \t size: \(sizeof(UInt64)) \t min: \(UInt64.min) \t max: \(UInt64.max)")

print("UInt \t size: \(sizeof(UInt)) \t min: \(UInt.min) \t max: \(UInt.max)")

let dVal = 1.1

dVal.dynamicType

let floatVal : Float = 1.1

let DoubleVal : Double = 1.1

print("Float \t size: \(sizeof(Float))")

print("Double \t size: \(sizeof(Double))")

let decimalVal = 10

let binaryVal = 0b1010

let octVal = 0o110

let hexval = 0x10

let exponentDouble1 = 12.12e1

let exponentDouble2 = 12.12e-1

let hexDecimalDouble = 0x12.3p1

//uint8Val = intVal

//uint8Val = UInt8.max + 1

uint8Val = UInt8(intVal)

let doubleRes = 1.34 + 5

let double1 = 1.34

let int1 = 5

let res = double1 + Double(int1)

typealias Distance = Int

let longDistance : Distance = 1

longDistance.dynamicType

Distance.min

Distance.max

let amiICool = true

if amiICool {

print("tks")

}

var doubleVal1 = 1.1

原文链接:http://www.maiziedu.com/wiki/swift/data/
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