swift 2.2基本数据类型
整数
1分快3彩票1.分为有符号整数和无符号整数;
2.有符号: Int8 Int16 Int32 Int64 Int;
1分快3彩票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);
1分快3彩票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;
1分快3彩票2.32位机,sizeof(Int)等于sizeof(Int32);
1分快3彩票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;
1分快3彩票2.Double 64位浮点数。
布尔值
1分快3彩票Bool(true false)
其他
1.类型转换;
2.类型别名;
1分快3彩票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
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