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authorIan Bertolacci <ian.bertolacci@gmail.com>2015-08-05 18:26:24 -0700
committerIan Bertolacci <ian.bertolacci@gmail.com>2015-08-05 18:26:24 -0700
commit171f179f6e2f720afbb2d9097bb78d6163b9c405 (patch)
treed083754fa90e2350446935ffdaf2ee98bd01bac6
parentb1a544d1f04fc6c9769037af5fd165e7032a2985 (diff)
parentfded8fbd6c01b22c4dd184db0647051dd818fb01 (diff)
Merge branch 'master' of github.com:adambard/learnxinyminutes-docs
-rw-r--r--scala.html.markdown115
-rw-r--r--swift.html.markdown57
2 files changed, 86 insertions, 86 deletions
diff --git a/scala.html.markdown b/scala.html.markdown
index e6638121..c482752d 100644
--- a/scala.html.markdown
+++ b/scala.html.markdown
@@ -5,6 +5,7 @@ contributors:
- ["George Petrov", "http://github.com/petrovg"]
- ["Dominic Bou-Samra", "http://dbousamra.github.com"]
- ["Geoff Liu", "http://geoffliu.me"]
+ - ["Ha-Duong Nguyen", "http://reference-error.org"]
filename: learn.scala
---
@@ -16,15 +17,16 @@ Scala - the scalable language
Set yourself up:
1) Download Scala - http://www.scala-lang.org/downloads
- 2) unzip/untar in your favourite location and put the bin subdir on the path
- 3) Start a scala REPL by typing scala. You should see the prompt:
+ 2) Unzip/untar to your favourite location and put the bin subdir in your `PATH` environment variable
+ 3) Start a Scala REPL by running `scala`. You should see the prompt:
scala>
- This is the so called REPL (Read-Eval-Print Loop). You may type any valid
- Scala expression into it, and the result will be printed. We will explain what
- Scala files look like further into this tutorial, but for now, let's start
- with some basics.
+ This is the so called REPL (Read-Eval-Print Loop). You may type any Scala
+ expression, and the result will be printed. We will explain what Scala files
+ look like further into this tutorial, but for now, let's start with some
+ basics.
+
*/
@@ -32,10 +34,10 @@ Scala - the scalable language
// 1. Basics
/////////////////////////////////////////////////
-// Single line comments start with two forward slashes
+// Single-line comments start with two forward slashes
/*
- Multi line comments, as you can already see from above, look like this.
+ Multi-line comments, as you can already see from above, look like this.
*/
// Printing, and forcing a new line on the next print
@@ -46,12 +48,12 @@ println(10)
print("Hello world")
// Declaring values is done using either var or val.
-// val declarations are immutable, whereas var's are mutable. Immutability is
+// val declarations are immutable, whereas vars are mutable. Immutability is
// a good thing.
val x = 10 // x is now 10
-x = 20 // error: reassignment to val
+x = 20 // error: reassignment to val
var y = 10
-y = 20 // y is now 20
+y = 20 // y is now 20
/*
Scala is a statically typed language, yet note that in the above declarations,
@@ -71,17 +73,17 @@ true
false
// Boolean operations
-!true // false
-!false // true
+!true // false
+!false // true
true == false // false
-10 > 5 // true
+10 > 5 // true
// Math is as per usual
-1 + 1 // 2
-2 - 1 // 1
-5 * 3 // 15
-6 / 2 // 3
-6 / 4 // 1
+1 + 1 // 2
+2 - 1 // 1
+5 * 3 // 15
+6 / 2 // 3
+6 / 4 // 1
6.0 / 4 // 1.5
@@ -120,12 +122,12 @@ s"We have $n apples" // => "We have 45 apples"
// Expressions inside interpolated strings are also possible
val a = Array(11, 9, 6)
-s"My second daughter is ${a(0) - a(2)} years old." // => "My second daughter is 5 years old."
+s"My second daughter is ${a(0) - a(2)} years old." // => "My second daughter is 5 years old."
s"We have double the amount of ${n / 2.0} in apples." // => "We have double the amount of 22.5 in apples."
-s"Power of 2: ${math.pow(2, 2)}" // => "Power of 2: 4"
+s"Power of 2: ${math.pow(2, 2)}" // => "Power of 2: 4"
// Formatting with interpolated strings with the prefix "f"
-f"Power of 5: ${math.pow(5, 2)}%1.0f" // "Power of 5: 25"
+f"Power of 5: ${math.pow(5, 2)}%1.0f" // "Power of 5: 25"
f"Square root of 122: ${math.sqrt(122)}%1.4f" // "Square root of 122: 11.0454"
// Raw strings, ignoring special characters.
@@ -171,12 +173,12 @@ def sq(x: Int) = x * x // Compiler can guess return type is Int
// Functions can have default parameters:
def addWithDefault(x: Int, y: Int = 5) = x + y
-addWithDefault(1, 2) // => 3
-addWithDefault(1) // => 6
+addWithDefault(1, 2) // => 3
+addWithDefault(1) // => 6
// Anonymous functions look like this:
-(x:Int) => x * x
+(x: Int) => x * x
// Unlike defs, even the input type of anonymous functions can be omitted if the
// context makes it clear. Notice the type "Int => Int" which means a function
@@ -193,8 +195,8 @@ sq(10) // => 100
val addOne: Int => Int = _ + 1
val weirdSum: (Int, Int) => Int = (_ * 2 + _ * 3)
-addOne(5) // => 6
-weirdSum(2, 4) // => 16
+addOne(5) // => 6
+weirdSum(2, 4) // => 16
// The return keyword exists in Scala, but it only returns from the inner-most
@@ -204,9 +206,9 @@ weirdSum(2, 4) // => 16
def foo(x: Int): Int = {
val anonFunc: Int => Int = { z =>
if (z > 5)
- return z // This line makes z the return value of foo!
+ return z // This line makes z the return value of foo!
else
- z + 2 // This line is the return value of anonFunc
+ z + 2 // This line is the return value of anonFunc
}
anonFunc(x) // This line is the return value of foo
}
@@ -218,19 +220,19 @@ def foo(x: Int): Int = {
1 to 5
val r = 1 to 5
-r.foreach( println )
+r.foreach(println)
r foreach println
// NB: Scala is quite lenient when it comes to dots and brackets - study the
// rules separately. This helps write DSLs and APIs that read like English
-(5 to 1 by -1) foreach ( println )
+(5 to 1 by -1) foreach (println)
// A while loops
var i = 0
-while (i < 10) { println("i " + i); i+=1 }
+while (i < 10) { println("i " + i); i += 1 }
-while (i < 10) { println("i " + i); i+=1 } // Yes, again. What happened? Why?
+while (i < 10) { println("i " + i); i += 1 } // Yes, again. What happened? Why?
i // Show the value of i. Note that while is a loop in the classical sense -
// it executes sequentially while changing the loop variable. while is very
@@ -239,19 +241,19 @@ i // Show the value of i. Note that while is a loop in the classical sense -
// A do while loop
do {
- println("x is still less than 10");
+ println("x is still less than 10")
x += 1
} while (x < 10)
// Tail recursion is an idiomatic way of doing recurring things in Scala.
// Recursive functions need an explicit return type, the compiler can't infer it.
// Here it's Unit.
-def showNumbersInRange(a:Int, b:Int):Unit = {
+def showNumbersInRange(a: Int, b: Int): Unit = {
print(a)
if (a < b)
showNumbersInRange(a + 1, b)
}
-showNumbersInRange(1,14)
+showNumbersInRange(1, 14)
// Conditionals
@@ -305,13 +307,13 @@ s(1)
(a, 2, "three")
// Why have this?
-val divideInts = (x:Int, y:Int) => (x / y, x % y)
+val divideInts = (x: Int, y: Int) => (x / y, x % y)
-divideInts(10,3) // The function divideInts gives you the result and the remainder
+divideInts(10, 3) // The function divideInts gives you the result and the remainder
// To access the elements of a tuple, use _._n where n is the 1-based index of
// the element
-val d = divideInts(10,3)
+val d = divideInts(10, 3)
d._1
@@ -359,7 +361,7 @@ class Dog(br: String) {
val mydog = new Dog("greyhound")
println(mydog.breed) // => "greyhound"
-println(mydog.bark) // => "Woof, woof!"
+println(mydog.bark) // => "Woof, woof!"
// The "object" keyword creates a type AND a singleton instance of it. It is
@@ -414,8 +416,8 @@ val otherGeorge = george.copy(phoneNumber = "9876")
def matchPerson(person: Person): String = person match {
// Then you specify the patterns:
case Person("George", number) => "We found George! His number is " + number
- case Person("Kate", number) => "We found Kate! Her number is " + number
- case Person(name, number) => "We matched someone : " + name + ", phone : " + number
+ case Person("Kate", number) => "We found Kate! Her number is " + number
+ case Person(name, number) => "We matched someone : " + name + ", phone : " + number
}
val email = "(.*)@(.*)".r // Define a regex for the next example.
@@ -446,7 +448,7 @@ def matchEverything(obj: Any): String = obj match {
case List(1, b, c) => s"Got a list with three elements and starts with 1: 1, $b, $c"
// You can nest patterns:
- case List(List((1, 2,"YAY"))) => "Got a list of list of tuple"
+ case List(List((1, 2, "YAY"))) => "Got a list of list of tuple"
}
// In fact, you can pattern match any object with an "unapply" method. This
@@ -493,7 +495,7 @@ sSquared.reduce (_+_)
// The filter function takes a predicate (a function from A -> Boolean) and
// selects all elements which satisfy the predicate
List(1, 2, 3) filter (_ > 2) // List(3)
-case class Person(name:String, age:Int)
+case class Person(name: String, age: Int)
List(
Person(name = "Dom", age = 23),
Person(name = "Bob", age = 30)
@@ -541,8 +543,8 @@ implicit def myImplicitFunction(breed: String) = new Dog("Golden " + breed)
// By itself, implicit keyword doesn't change the behavior of the value, so
// above values can be used as usual.
-myImplicitInt + 2 // => 102
-myImplicitFunction("Pitbull").breed // => "Golden Pitbull"
+myImplicitInt + 2 // => 102
+myImplicitFunction("Pitbull").breed // => "Golden Pitbull"
// The difference is that these values are now eligible to be used when another
// piece of code "needs" an implicit value. One such situation is implicit
@@ -570,8 +572,8 @@ def foo[T : C] = ...
// implicit conversion of type A => B, where A is the type of obj, and B has a
// method called "method", that conversion is applied. So having
// myImplicitFunction above in scope, we can say:
-"Retriever".breed // => "Golden Retriever"
-"Sheperd".bark // => "Woof, woof!"
+"Retriever".breed // => "Golden Retriever"
+"Sheperd".bark // => "Woof, woof!"
// Here the String is first converted to Dog using our function above, and then
// the appropriate method is called. This is an extremely powerful feature, but
@@ -594,7 +596,7 @@ import scala.collection.immutable._
import scala.collection.immutable.{List, Map}
// Rename an import using '=>'
-import scala.collection.immutable.{ List => ImmutableList }
+import scala.collection.immutable.{List => ImmutableList}
// Import all classes, except some. The following excludes Map and Set:
import scala.collection.immutable.{Map => _, Set => _, _}
@@ -629,13 +631,8 @@ writer.close()
## Further resources
-[Scala for the impatient](http://horstmann.com/scala/)
-
-[Twitter Scala school](http://twitter.github.io/scala_school/)
-
-[The scala documentation](http://docs.scala-lang.org/)
-
-[Try Scala in your browser](http://scalatutorials.com/tour/)
-
-Join the [Scala user group](https://groups.google.com/forum/#!forum/scala-user)
-
+* [Scala for the impatient](http://horstmann.com/scala/)
+* [Twitter Scala school](http://twitter.github.io/scala_school/)
+* [The scala documentation](http://docs.scala-lang.org/)
+* [Try Scala in your browser](http://scalatutorials.com/tour/)
+* Join the [Scala user group](https://groups.google.com/forum/#!forum/scala-user)
diff --git a/swift.html.markdown b/swift.html.markdown
index ffc57e69..509c9d2f 100644
--- a/swift.html.markdown
+++ b/swift.html.markdown
@@ -4,6 +4,7 @@ contributors:
- ["Grant Timmerman", "http://github.com/grant"]
- ["Christopher Bess", "http://github.com/cbess"]
- ["Joey Huang", "http://github.com/kamidox"]
+ - ["Anthony Nguyen", "http://github.com/anthonyn60"]
filename: learnswift.swift
---
@@ -26,7 +27,9 @@ import UIKit
// TODO: Do something soon
// FIXME: Fix this code
-println("Hello, world")
+// 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
// variables (var) value can change after being set
// constants (let) value can NOT be changed after being set
@@ -46,12 +49,12 @@ let piText = "Pi = \(π), Pi 2 = \(π * 2)" // String interpolation
// Build Specific values
// uses -D build configuration
#if false
- println("Not printed")
+ print("Not printed")
let buildValue = 3
#else
let buildValue = 7
#endif
-println("Build value: \(buildValue)") // Build value: 7
+print("Build value: \(buildValue)") // Build value: 7
/*
Optionals are a Swift language feature that allows you to store a `Some` or
@@ -69,7 +72,7 @@ var someOptionalString2: Optional<String> = "optional"
if someOptionalString != nil {
// I am not nil
if someOptionalString!.hasPrefix("opt") {
- println("has the prefix")
+ print("has the prefix")
}
let empty = someOptionalString?.isEmpty
@@ -138,21 +141,21 @@ var emptyMutableDictionary = [String: Float]() // var == mutable
let myArray = [1, 1, 2, 3, 5]
for value in myArray {
if value == 1 {
- println("One!")
+ print("One!")
} else {
- println("Not one!")
+ print("Not one!")
}
}
// for loop (dictionary)
var dict = ["one": 1, "two": 2]
for (key, value) in dict {
- println("\(key): \(value)")
+ print("\(key): \(value)")
}
// for loop (range)
for i in -1...shoppingList.count {
- println(i)
+ print(i)
}
shoppingList[1...2] = ["steak", "peacons"]
// use ..< to exclude the last number
@@ -165,7 +168,7 @@ while i < 1000 {
// do-while loop
do {
- println("hello")
+ print("hello")
} while 1 == 2
// Switch
@@ -222,8 +225,8 @@ let pricesTuple = getGasPrices()
let price = pricesTuple.2 // 3.79
// Ignore Tuple (or other) values by using _ (underscore)
let (_, price1, _) = pricesTuple // price1 == 3.69
-println(price1 == pricesTuple.1) // true
-println("Gas price: \(price)")
+print(price1 == pricesTuple.1) // true
+print("Gas price: \(price)")
// Variadic Args
func setup(numbers: Int...) {
@@ -251,7 +254,7 @@ func swapTwoInts(inout a: Int, inout b: Int) {
var someIntA = 7
var someIntB = 3
swapTwoInts(&someIntA, &someIntB)
-println(someIntB) // 7
+print(someIntB) // 7
//
@@ -305,7 +308,7 @@ struct NamesTable {
// Structures have an auto-generated (implicit) designated initializer
let namesTable = NamesTable(names: ["Me", "Them"])
let name = namesTable[1]
-println("Name is \(name)") // Name is Them
+print("Name is \(name)") // Name is Them
//
// MARK: Classes
@@ -386,7 +389,7 @@ let aShape = mySquare as Shape
// compare instances, not the same as == which compares objects (equal to)
if mySquare === mySquare {
- println("Yep, it's mySquare")
+ print("Yep, it's mySquare")
}
// Optional init
@@ -409,13 +412,13 @@ class Circle: Shape {
}
var myCircle = Circle(radius: 1)
-println(myCircle?.getArea()) // Optional(3)
-println(myCircle!.getArea()) // 3
+print(myCircle?.getArea()) // Optional(3)
+print(myCircle!.getArea()) // 3
var myEmptyCircle = Circle(radius: -1)
-println(myEmptyCircle?.getArea()) // "nil"
+print(myEmptyCircle?.getArea()) // "nil"
if let circle = myEmptyCircle {
// will not execute since myEmptyCircle is nil
- println("circle is not nil")
+ print("circle is not nil")
}
@@ -447,7 +450,7 @@ enum BookName: String {
case John = "John"
case Luke = "Luke"
}
-println("Name: \(BookName.John.rawValue)")
+print("Name: \(BookName.John.rawValue)")
// Enum with associated Values
enum Furniture {
@@ -467,9 +470,9 @@ enum Furniture {
}
var desk: Furniture = .Desk(height: 80)
-println(desk.description()) // "Desk with 80 cm"
+print(desk.description()) // "Desk with 80 cm"
var chair = Furniture.Chair("Foo", 40)
-println(chair.description()) // "Chair of Foo with 40 cm"
+print(chair.description()) // "Chair of Foo with 40 cm"
//
@@ -522,7 +525,7 @@ extension Square: Printable {
}
}
-println("Square: \(mySquare)")
+print("Square: \(mySquare)")
// You can also extend built-in types
extension Int {
@@ -535,8 +538,8 @@ extension Int {
}
}
-println(7.customProperty) // "This is 7"
-println(14.multiplyBy(3)) // 42
+print(7.customProperty) // "This is 7"
+print(14.multiplyBy(3)) // 42
// Generics: Similar to Java and C#. Use the `where` keyword to specify the
// requirements of the generics.
@@ -550,7 +553,7 @@ func findIndex<T: Equatable>(array: [T], valueToFind: T) -> Int? {
return nil
}
let foundAtIndex = findIndex([1, 2, 3, 4], 3)
-println(foundAtIndex == 2) // true
+print(foundAtIndex == 2) // true
// Operators:
// Custom operators can start with the characters:
@@ -566,9 +569,9 @@ prefix func !!! (inout shape: Square) -> Square {
}
// current value
-println(mySquare.sideLength) // 4
+print(mySquare.sideLength) // 4
// change side length using custom !!! operator, increases size by 3
!!!mySquare
-println(mySquare.sideLength) // 12
+print(mySquare.sideLength) // 12
```