learning swift pdf

amazing!Like what. When you ask for a square root of a number, you still want to use back the original function performoperation. However, this function requires a function that includes two Double types. To find the square root only need to pass in a parameter, ah, then to transform this function, in writing a function of the same name Performoperation. It is then defined as just a need for a form of participation.Note: Swift supports multiple funct

)")//}Yyz:toronto PearsonLhr:london HeathrowFor more information on for-in loops, see for loops.//By accessing the keys or the Values property, we can also traverse the dictionary key or value://For Airportcode in Airports.keys {Print ("Airport code: \ (Airportcode)")//}Airport Code:yyzAirport CODE:LHR//For Airportname in Airports.values {Print ("Airport name: \ (airportname)")//}Airport Name:toronto PearsonAirport Name:london HeathrowIf we just need to use a dictionary key collection or a value

MethodA method is a function that is associated with a particular type. Classes, structs, enumerations can define instance methods and type methods. The type method is similar to the class method in OC.Structs and enumerations can also be defined as a significant difference between Swift and C/oc, in which only classes can define methods.Instance methodAn instance method is a method that enumerates instances from a class instance or struct body instan

Let strings = numbers. map { //Map function after () can be omitted (var number), String in var output = "" While number > 0 { Output = String (number% 10) + output Number/= 10 } return Output } /* Capture Value * Closures can be captured to defined constants and variables according to the environment context. Closures can reference and modify these captured constants and variables, * Even if defined as a constant in the original scope or the variable no longer ex

exists and is replaced by the argument and the return value.in. Note that if there isin, even if there are no parameters, the return value must be(), or you will get an error. SummarizeLike Objective-c's Fuckingblock, Swift came out and Fuckingclosure was born. Summarizes the common syntax and format of Closure: As a variableVarClosurename:(parametertypes) (returntype)As a variable of an optional typeVarClosurename:((parametertypes) (returntype))?

will find that it implies some small pits ~Below, the small soup I bring to you under swift Special Single example implementation solution ~ Soup I mean love oh ~ Wow Quack!2.Swift Featured Edition// 定义一个私有的静态成员private static let instance = NetworkTools()class func sharedNetworkTools() -> NetworkTools { return instance}is not good simple!!!In Swift, it let is

possible to do arithmetic operations on variables of different numeric types, and when you do arithmetic on variables, the types of all variables must be the same, and if the variable types are different, you must explicitly convert some of the variables to type:1 var sum = Double (three) + ZeropointforteenAs can be seen from the above, the use of a Double (three) of an Int type of three "conversion" into a floating-point number, here, the reason for the conversion is quoted, because it does no

be widely circulated 1386.1 About virology, research tells us what 1396.2 Get the number and content of shares 1406.3 Exploring the characteristics of the propagation 1496.3.1 Exploring Image Data 1496.3.2 Explore Heading 1526.3.3 exploring the content of the story 1566.4 Building a predictive model for content scoring 1576.5 Summary 162The 7th Chapter uses machine learning to predict the stock market 1637.1 Types of market Analysis 1647.2 About the

to defined constants and variables according to the environment context. Closures can reference and modify these captured constants and variables,* Even if defined as a constant in the original scope or the variable no longer exists (very good).* The simplest form of closure in Swift is a nested function.*/Func increment (#amount: int), ((), int) {var total = 0Func Incrementamount (), Int {Total + = amount//Total is a variable in the body of an exter

IF statement and is designed to improve the readability of the program The guard statement must have an else statement with the following syntax: When the conditional expression is true, skips the contents of the Else statement and executes the statement group contents The conditional expression is false when the content in the Else statement is executed, and the jump statement is typically return, break, continue, and throw Format: Guard condit

the interval contains the first value and does not contain the last valueThe practicality of the semi-open interval is that when you use a 0-based list (such as 0), it is very convenient to get from 0 to the list lengthLogic and operatorsWhen the logical operators (a B) express that only the values of A and B are true, the value of the entire expression is true, so long as any one value is false, the value of the entire expression is false, in fact, if the first value is false, that You do not

condition parameter is evaluated only in debug mode, and its message parameter is evaluated only when the condition parameter is false.Automatic closures allow you to delay the evaluation because the code snippet will not be executed until you call the closure. Latency evaluation is useful for code that has side effects (Side Effect) and high computational costs because it allows you to control the timing of code execution. The following code shows how the closure is evaluated for delay.var cus

name, and then add the type name.var welcomemessage:stringThis variable can only store values of type String.The colon in the declaration represents "Yes ... Type ", so this line of code can be understood as:"Declares a type is a String, and the name is a variable of welcomemessage. ”"Type is String" means "a value of any string type can be stored." ”The Welcomemessage variable can now be set to any string:Welcomemessage = "Hello"You can define multiple variables of the same type in a row, sepa

value to subsequent members in turn. The initial value of a member can be obtained through rawvalue, such as:Let Earthsorder = Planet.Earth.rawValue// Earthsorder is 3If you define an enumeration type that has an original value type, the enumeration automatically gets an initialization method that accepts the original value type parameter and returns an enumeration member or nil, which you can use to create an enumeration instance:7 )// possibleplanet is of type Planet? and equals Planet.uran

")Break aa;//}}}---------------------function---------Func (keyword of the function)The format of the switch function definition func function name (parameter name:), return value type {statement block}Func sayhi (name:string)->string{return name + "Hello"}var sa = Sayhi ("World")println (SA)Sum of two numbersFunc sum (summ1:int, Summ2:int)->int{return SUMM1 + summ2}var summ = SUM (10,10)println (Summ)Return value if multiple can be returned in tuplesFunc CountNumber () (Saa:int,sbb:int){var saa

itself and cannot be used unless it is enclosed in an accented (') notation.The following 4 keywords are common to swift languages.L keywords related to declaration: class, Deinit, enum, and so on.L keywords related to statements: Break, case, continue and so on.L Expressions and Type keywords: as, catch, DynamicType, false, and so on.L keywords used in specific contexts: associativity, convenience, dynamic, and so on.The keywords in