Swift基础语法的学习
1.Swift中的模块化的标注;
在OC中使用是:
#pragma mark - 标注一段的相关功能;
在Swift中使用的是:
MARK:- 标注一段的相关功能;
实现的效果如下图:
2.Swift的基本“输入”,“输出”语句,常量,字符串,数学运算符,布尔类型等等
//MARK:- 隐式声明类型 //MARK:- 输出语句 //swift的输出语句 print("MeiNv"); print("!"); //print此语句自带换行符 //MARK:- 定义变量 //定义变量给变量赋值(swift会自动推断变量的类型) var x = 12 print(x); var y = 42.0 print(y); x = 38; y = 99; print(x); print(y); //变量的结果赋值给变量(如果两个变量的类型不相同应该强转一下,否则会报错) y = Double(x); print(y); //MARK:- 常量 //常量使用let修饰 let z = x; print(z); //z = 4; //常量是不能改变的量,如果给常量赋值会造成错误 //查看数值类型的上下线 print(Int.min); print(Int.max); //数值转字符串 var t = 123; var s = String(t); print(s); //字符串转数值 var u = Int(s); print(u); //MARK:- 显示声明类型 var myNewNumber : Double = 3; print(myNewNumber); let myState = "i love"; let myBobdy : String = "yuanyuan"; let scentence = myState + " " + myBobdy + "."; print(scentence); let myStr : Character = "A"; let myFavoriteLetters = String(myStr) + String(myStr); print(myFavoriteLetters); //MARK:- 数学运算符 let addition = 2 + 2; print(addition); let subtraction = 4 - 3; print(subtraction); let multiplication = 10 * 5; print(multiplication); let division = 24/6; print(division); let modulo = 23 % 4; print(modulo); //swift中可以将求余运算用于Double值 let modulo1 = 23 % 4; print(modulo); //数值前边加正号或者负号,即表示正数或者负数 var positiveNumber : Int = +33; var positiveNumber1 : Int = -55; print(positiveNumber); print(positiveNumber1); let r = 3 + 5*9; print(r); let r1 = 48 / 5.0; //此时r1被指定为Double类型 print(r1); //MARK:- 数值表示 //二进制(0b)、八进制(0o)、十六进制(0x) let binaryNumber = 0b110011; print(binaryNumber); let octalNumber = 0o12; print(octalNumber); let hexadecimalNumber = 0x32; print(hexadecimalNumber); //Bool类型结果:true 和 false print(100 > 50); print(66.2 < 20); let result : Bool = "this thing" == "this hg"; print(result); //嵌入表示法\() let myFavoriteStr = "new land"; let myFood = "i love"; print("when i \(myFavoriteLetters)\(myFood) years ago"); //重定义别名 typealias eightBits = UInt8; var reg : eightBits = 0; //元组:一组组合方式 let myDreamCar = (2014,"mercedes-Ben","yuanyuan"); print(myDreamCar); print(myDreamCar.0); //访问元组中的元素 //可选类型(在相关类型后边加?即可) var v : Int? = nil; //MARK:- 使用集合 let candyJar = ["Apple","goole bears","happy"]; print(candyJar);
基本语法的学习就到这里了,稍后继续。。。。