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authorC. Bess <cbess@company.com>2015-11-09 18:09:48 -0600
committerC. Bess <cbess@company.com>2015-11-09 18:09:48 -0600
commit618f8f5badfded04ee1edb7c24ccf24ea61a947b (patch)
tree997b87d12347df6c7d2b01e74011a074cc5ad6c7 /swift.html.markdown
parentdf0992d72c2a28f140e6ff9681c505f36e19249a (diff)
- update Swift examples
- update to upgrade to Swift 2.1 - code cleanup
Diffstat (limited to 'swift.html.markdown')
-rw-r--r--swift.html.markdown81
1 files changed, 38 insertions, 43 deletions
diff --git a/swift.html.markdown b/swift.html.markdown
index f2e9d04c..a39bc1d6 100644
--- a/swift.html.markdown
+++ b/swift.html.markdown
@@ -32,7 +32,7 @@ import UIKit
// In Swift 2, println and print were combined into one print method. Print automatically appends a new line.
print("Hello, world") // println is now print
-print("Hello, world", appendNewLine: false) // printing without appending a newline
+print("Hello, world", terminator: "") // printing without appending a newline
// variables (var) value can change after being set
// constants (let) value can NOT be changed after being set
@@ -60,14 +60,14 @@ let piText = "Pi = \(π), Pi 2 = \(π * 2)" // String interpolation
print("Build value: \(buildValue)") // Build value: 7
/*
- Optionals are a Swift language feature that either contains a value,
- or contains nil (no value) to indicate that a value is missing.
- A question mark (?) after the type marks the value as optional.
+Optionals are a Swift language feature that either contains a value,
+or contains nil (no value) to indicate that a value is missing.
+A question mark (?) after the type marks the value as optional.
- Because Swift requires every property to have a value, even nil must be
- explicitly stored as an Optional value.
+Because Swift requires every property to have a value, even nil must be
+explicitly stored as an Optional value.
- Optional<T> is an enum.
+Optional<T> is an enum.
*/
var someOptionalString: String? = "optional" // Can be nil
// same as above, but ? is a postfix operator (syntax candy)
@@ -84,9 +84,9 @@ if someOptionalString != nil {
someOptionalString = nil
/*
- Trying to use ! to access a non-existent optional value triggers a runtime
- error. Always make sure that an optional contains a non-nil value before
- using ! to force-unwrap its value.
+Trying to use ! to access a non-existent optional value triggers a runtime
+error. Always make sure that an optional contains a non-nil value before
+using ! to force-unwrap its value.
*/
// implicitly unwrapped optional
@@ -120,8 +120,8 @@ anyObjectVar = "Changed value to a string, not good practice, but possible."
//
/*
- Array and Dictionary types are structs. So `let` and `var` also indicate
- that they are mutable (var) or immutable (let) when declaring these types.
+Array and Dictionary types are structs. So `let` and `var` also indicate
+that they are mutable (var) or immutable (let) when declaring these types.
*/
// Array
@@ -178,8 +178,8 @@ while i < 1000 {
i *= 2
}
-// do-while loop
-do {
+// repeat-while loop
+repeat {
print("hello")
} while 1 == 2
@@ -209,22 +209,22 @@ default: // required (in order to cover all possible input)
// Function with Swift header docs (format as reStructedText)
/**
- A greet operation
+A greet operation
- - A bullet in docs
- - Another bullet in the docs
+- A bullet in docs
+- Another bullet in the docs
- :param: name A name
- :param: day A day
- :returns: A string containing the name and day value.
+:param: name A name
+:param: day A day
+:returns: A string containing the name and day value.
*/
func greet(name: String, day: String) -> String {
return "Hello \(name), today is \(day)."
}
-greet("Bob", "Tuesday")
+greet("Bob", day: "Tuesday")
// similar to above except for the function parameter behaviors
-func greet2(#requiredName: String, externalParamName localParamName: String) -> String {
+func greet2(requiredName requiredName: String, externalParamName localParamName: String) -> String {
return "Hello \(requiredName), the day is \(localParamName)"
}
greet2(requiredName: "John", externalParamName: "Sunday")
@@ -247,14 +247,14 @@ func getGasPrices2() -> (lowestPrice: Double, highestPrice: Double, midPrice: Do
let pricesTuple2 = getGasPrices2()
let price2 = pricesTuple2.lowestPrice
let (_, price3, _) = pricesTuple2
-println(pricesTuple2.highestPrice == pricesTuple2.1) // true
-println("Highest gas price: \(pricesTuple2.highestPrice)")
+print(pricesTuple2.highestPrice == pricesTuple2.1) // true
+print("Highest gas price: \(pricesTuple2.highestPrice)")
// Variadic Args
func setup(numbers: Int...) {
// its an array
- let number = numbers[0]
- let argCount = numbers.count
+ let _ = numbers[0]
+ let _ = numbers.count
}
// Passing and returning functions
@@ -275,7 +275,7 @@ func swapTwoInts(inout a: Int, inout b: Int) {
}
var someIntA = 7
var someIntB = 3
-swapTwoInts(&someIntA, &someIntB)
+swapTwoInts(&someIntA, b: &someIntB)
print(someIntB) // 7
@@ -303,23 +303,17 @@ numbers = numbers.map({ number in 3 * number })
print(numbers) // [3, 6, 18]
// Trailing closure
-numbers = sorted(numbers) { $0 > $1 }
+numbers = numbers.sort { $0 > $1 }
print(numbers) // [18, 6, 3]
-// Super shorthand, since the < operator infers the types
-
-numbers = sorted(numbers, < )
-
-print(numbers) // [3, 6, 18]
-
//
// MARK: Structures
//
// Structures and classes have very similar capabilities
struct NamesTable {
- let names = [String]()
+ let names: [String]
// Custom subscript
subscript(index: Int) -> String {
@@ -472,9 +466,10 @@ enum Suit {
// when the variable is explicitly declared
var suitValue: Suit = .Hearts
-// Non-Integer enums require direct raw value assignments
+// String enums can have direct raw value assignments
+// or their raw values will be derived from the Enum field
enum BookName: String {
- case John = "John"
+ case John
case Luke = "Luke"
}
print("Name: \(BookName.John.rawValue)")
@@ -518,7 +513,7 @@ protocol ShapeGenerator {
// Protocols declared with @objc allow optional functions,
// which allow you to check for conformance
@objc protocol TransformShape {
- optional func reshaped()
+ optional func reshape()
optional func canReshape() -> Bool
}
@@ -531,9 +526,9 @@ class MyShape: Rect {
// Place a question mark after an optional property, method, or
// subscript to gracefully ignore a nil value and return nil
// instead of throwing a runtime error ("optional chaining").
- if let allow = self.delegate?.canReshape?() {
+ if let reshape = self.delegate?.canReshape?() where reshape {
// test for delegate then for method
- self.delegate?.reshaped?()
+ self.delegate?.reshape?()
}
}
}
@@ -546,7 +541,7 @@ class MyShape: Rect {
// `extension`s: Add extra functionality to an already existing type
// Square now "conforms" to the `Printable` protocol
-extension Square: Printable {
+extension Square: CustomStringConvertible {
var description: String {
return "Area: \(self.getArea()) - ID: \(self.identifier)"
}
@@ -571,8 +566,8 @@ print(14.multiplyBy(3)) // 42
// Generics: Similar to Java and C#. Use the `where` keyword to specify the
// requirements of the generics.
-func findIndex<T: Equatable>(array: [T], valueToFind: T) -> Int? {
- for (index, value) in enumerate(array) {
+func findIndex<T: Equatable>(array: [T], _ valueToFind: T) -> Int? {
+ for (index, value) in array.enumerate() {
if value == valueToFind {
return index
}