How to create an empty array in Swift

Question

I m really confused with the ways we create an array in Swift  Could you please tell me how many ways to create an empty array with some detail

User · Answer

Initiating an array with a predefined count:

Array(repeating: 0, count: 10)

I often use this for mapping statements where I need a specified number of mock objects. For example,

let myObjects: [MyObject] = Array(repeating: 0, count: 10).map { _ in return MyObject() }

User · Answer

Here are some common tasks in Swift 4 you can use as a reference until you get used to things       let emptyArray    String        let emptyDouble   Double            let preLoadArray   Array repeating  0  count  10     initializes array with 10 default values of the number 0      let arrayMix    1   two   3  as  Any      var arrayNum    1  2  3      var array     1    two    3       array 1     2      array append  4       array      5    6       array insert  0   at  0      array 0     Zero      array insert contentsOf    -3    -2    -1    at  0      array remove at  0      array removeLast       array     Replaces all indexes with this       array removeAll        for item in arrayMix           print item             for  index  element  in array enumerated             print index          print element             for  index     in arrayNum enumerated   reversed             arrayNum remove at  index             let words    these words will be objects in an array  components separatedBy           print words 1        var names     Jemima    Peter    David    Kelly    Isabella    Adam       names sort      sorts names in alphabetical order      let nums    1  1234  12  123  0  999      print nums sorted       sorts numbers from lowest to highest

User · Answer

you can remove the array content with passing the array index or you can remove all      var array    String        print array      array append  MY NAME       print array      array removeFirst       print array      array append  MY NAME       array removeLast       array append  MY NAME1       array append  MY NAME2       print array      array removeAll       print array

User · Answer

As per Swift 5         An array of  Int  elements     let oddNumbers    1  3  5  7  9  11  13  15          An array of  String  elements     let streets     Albemarle    Brandywine    Chesapeake           Shortened forms are preferred     var emptyDoubles   Double               The full type name is also allowed     var emptyFloats  Array lt Float gt    Array

User · Answer

var myArr1    AnyObject      can store any object   var myArr2    String      can store only string

User · Answer

Swift 5 There are three  3  ways to create a empty array in Swift and shorthand syntax way is always preferred  Method 1  Shorthand Syntax var arr    Int     Method 2  Array Initializer var arr   Array lt Int gt     Method 3  Array with an Array Literal var arr  Int        Method 4   Credit goes to  BallpointBen var arr Array lt Int gt

User · Answer

Swift 5     Create an empty array var emptyArray    String        Add values to array by appending  Adds values as the last element  emptyArray append  Apple   emptyArray append  Oppo       Add values to array by inserting  Adds to a specified position of the list  emptyArray insert  Samsung   at  0      Remove elements from an array by index number emptyArray remove at  2      Remove elements by specifying the element if let removeElement   emptyArray firstIndex of   Samsung         emptyArray remove at  removeElement      A similar answer is given but that doesn t work for the latest version of Swift  Swift 5   so here is the updated answer  Hope it helps

User · Answer

Here you go   var yourArray    String      The above also works for other types and not just strings  It s just an example   Adding Values to It  I presume you ll eventually want to add a value to it   yourArray append  String Value     Or  let someString    You can also pass a string variable  like this   yourArray append someString    Add by Inserting  Once you have a few values  you can insert new values instead of appending  For example  if you wanted to insert new objects at the beginning of the array  instead of appending them to the end    yourArray insert  Hey  I m first    atIndex  0    Or you can use variables to make your insert more flexible   let lineCutter    I m going to be first soon   let positionToInsertAt   0 yourArray insert lineCutter  atIndex  positionToInsertAt    You May Eventually Want to Remove Some Stuff  var yourOtherArray     MonkeysRule    RemoveMe    SwiftRules   yourOtherArray remove at  1    The above works great when you know where in the array the value is  that is  when you know its index value   As the index values begin at 0  the second entry will be at index 1   Removing Values Without Knowing the Index  But what if you don t  What if yourOtherArray has hundreds of values and all you know is you want to remove the one equal to  RemoveMe    if let indexValue   yourOtherArray index of   RemoveMe         yourOtherArray remove at  indexValue      This should get you started

User · Answer

Array in swift is written  as   Array  lt  Element       where Element is the type of values the array is allowed to store    Array can be initialized as     let emptyArray    String     It shows that its an array of type string  The type of the emptyArray variable is inferred to be  String  from the type of the initializer   For Creating the array of type string with elements   var groceryList   String      Eggs    Milk    groceryList has been initialized with two items  The groceryList variable is declared as    an array of string values     written as  String    This particular array has specified a value type of String  it is allowed to store String values only   There are various properities of array like    - To check if array has elements  If array is empty or not   isEmpty property  Boolean   for checking whether the count property is equal to 0   if groceryList isEmpty       print  The groceryList list is empty      else       print  The groceryList is not empty        - Appending adding  elements in array  You can add a new item to the end of an array by calling the array   s append     method   groceryList append  Flour     groceryList now contains 3 items   Alternatively  append an array of one or more compatible items with the addition assignment operator        groceryList      Baking Powder     groceryList now contains 4 items  groceryList      Chocolate Spread    Cheese    Peanut Butter     groceryList now contains 7 items

User · Answer

If you want to declare an empty array of string type you can do that in 5 different way -  var myArray  Array lt String gt    Array   var myArray    String    var myArray   String       var myArray   Array lt String gt    var myArray Array lt String gt         Array of any type   -      var myArray  Array lt AnyObject gt    Array       var myArray    AnyObject        var myArray   AnyObject           var myArray   Array lt AnyObject gt        var myArray Array lt AnyObject gt         Array of Integer type   -      var myArray  Array lt Int gt    Array       var myArray    Int        var myArray   Int           var myArray   Array lt Int gt        var myArray Array lt Int gt

User · Answer

You could use  var firstNames   String

User · Answer

Compatible with  Xcode 6 0 1   You can create an empty array by specifying the Element type of your array in the declaration    For example      Shortened forms are preferred var emptyDoubles   Double           The full type name is also allowed var emptyFloats  Array lt Float gt    Array     Example from the apple developer page  Array    Hope this helps anyone stumbling onto this page

User · Answer

There are 2 major ways to create intialize an array in swift   var myArray    Double      This would create an array of Doubles   var myDoubles    Double  count  5  repeatedValue  2 0    This would create an array of 5 doubles  all initialized with the value of 2 0

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