Swift Language reviews four-closure

Summary: The whole closure function is to simplify the language expression form.

First, closure of the simplification

Closure expression syntax have the following general form:

• {(), in
• }

• Reversednames = names.sorted (by: {(s1:string, s2:string)-Bool in
• return s1 > S2
• })

Because The sorting closure is passed as an argument to a method, Swift can infer the types of its parameters and the type Of the value it returns.

Reversednames = names.sorted (by: {S1, s2 in return s1 > s2})

Implicit Returns from Single-expression Closures

Reversednames = names.sorted (by: {S1, s2 in S1 > s2})

Shorthand Argument Names

Swift automatically provides shorthand argument names to inline closures, which can is used to refer to the values of the Closure ' s arguments by the names $, $, $, and so on.

Reversednames = names.sorted (by: {$ > $})

Operator Methods

Reversednames = names.sorted (by: >)

Second, drag-tail transformation

• Func somefunctionthattakesaclosure (Closure: ()-Void) {
• function body goes here
• }
• Here's how to call the This function without using a trailing closure:
• Somefunctionthattakesaclosure (Closure: {
• Closure ' s body goes here
• })
• Here's how to call the This function with a trailing closure instead:
• Somefunctionthattakesaclosure () {
• Trailing closure ' s body goes here
• }

The implementation of closures is outside the list of function parameters;

Streamline again

Reversednames = names.sorted () {$ > $}

Reversednames = names.sorted {$ > $}

Fully removed

• Let strings = Numbers.map {(number), String in
• var number = number
• var output = ""
• Repeat {
• Output = digitnames[number% 10]! + Output
• Number/= 10
• } while number > 0
• Return output
• }

Closures is Reference Types

Whenever assign a function or a closure to a constant or a variable and you are actually setting that constant or variabl E to is a reference to the function or closure.

Escaping Closures

Asynchronous Solutions

Autoclosures

An expression statement

• Customersinline is ["Ewa", "Barry", "Daniella"]
• Func Serve (Customer Customerprovider: @autoclosure (), String) {
• Print ("Now Serving \ (Customerprovider ())!")
• }
• Serve (Customer:customersInLine.remove (at:0))
• Prints "Now Serving ewa!"

Swift Language reviews four-closure