Array
Declaring
// Explicitly var myArrayOfNames: [String] // Or Explicitly initialized var myArrayOfNames: [String] = [String]() // Or Explicitly initialized with values var myArrayOfNames: [String] = ["Mark", "Bob", "Matt"] // Implicitly var myArrayOfNames = [String]() // Or Implicitly initialized with values var myArrayOfNames = ["Mark", "Bob", "Matt"] // Or with values (3 values with "No name yet") var myArrayOfNames = [String] (count: 3, repeatedValue: "No name yet")
Modifying
// Add 3 names myArrayOfNames = ["Mark", "Bob", "Matt"] // Add one more to the end of the array myArrayOfNames.append("Jeff") // Add two more to the end of the array myArrayOfNames += ["Julie", "Patty"] // Add a name so it's the 2nd in the array myArrayOfNames.insert("Patrick", atIndex: 1) // Change the 4th name myArrayOfNames[3] = "Courtney" // Remove the 5th name myArrayOfNames.removeAtIndex(4) print("I have \(myArrayOfNames.count) items in my array") print("The 2nd name is \(myArrayOfNames[1]).")
Iterating
for name in myArrayOfNames { print(name) } // Just a range of indexes for name in myArrayOfNames[0...2] { print(name) } // Get the index position and the value for (index, name) in myArrayOfNames.enumerate() { print("\(name) is at position \(index)") }
Dictionary
Declaring
// Say I want to hold Name and Age of a person. // Explicitly var peopleDictionary: [String:Int] // Explicitly initialize an empty dictionary var peopleDictionary: [String:Int] = [String:Int]() // Implicitly var peopleDictionary = [String:Int]() // Implicitly with values var peopleDictionary = ["Mark":44, "Bob":51, "Matt":45]
Modifying
// Add 3 people peopleDictionary = ["Mark":44, "Bob":51, "Matt":45] // Add one more peopleDictionary["Jeff"] = 44 // Change Courtney's age peopleDictionary["Courtney"] = 30 // Change Courtney's age and get the previous age if let oldValue = peopleDictionary.updateValue(32, forKey: "Courtney") { print("The old value for Courtney was \(oldValue).") } // Remove Jeff peopleDictionary["Jeff"] = nil print("I have \(peopleDictionary.count) items in my dictionary") print("The age of Mark is \(peopleDictionary["Mark"]!).")
Set
Note: Not going to cover too much because I will probably use this less than arrays and dictionaries.How they are different:
- Stores unique values (can not store duplicate values)
- Not ordered (You insert an item, no guarantee where it will end up in the collection.)
Declaring
// Explicitly var mySetOfNames: Set<String> // Or Explicitly initialized var mySetOfNames: Set<String> = Set<String>() // Or Explicitly initialized with values var mySetOfNames: Set<String> = ["Mark", "Bob", "Matt"] // Implicitly var mySetOfNames = Set<String>() // Or Implicitly initialized with values (Still need to say it is a Set) var mySetOfNames: Set = ["Mark", "Bob", "Matt"]
Modifying
// Add a name mySetOfNames.insert("Patrick") // Remove a name mySetOfNames.remove("Mark") print("I have \(mySetOfNames.count) items in my set") for name in mySetOfNames { print(name) }(Updated for Swift 2.2)
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