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Cent Build Status CocoaPods


Cent is a library that extends certain Swift object types using the extension feature and gives its two cents to Swift language.

Dollar is a Swift library that provides useful functional programming helper methods without extending any built in objects. It is similar to Lo-Dash or Underscore.js in Javascript.



Using cocoapods version 0.36.x or greater

Add pod 'Cent' to your Podfile and run pod install. Add use_frameworks! to the end of the Podfile. Requires cocoapod version 0.36.x or greater.

Using Swift Package Manager

Add the following dependency .Package(url: "https://github.com/ankurp/Cent", majorVersion: 6, minor: 0) to your Package.swift file and then run swift build. Requires swift version 2.2 or greater that you can install from https://swift.org

Using git submodule

  1. If you are using git then add Cent as a submodule using git submodule add https://github.com/ankurp/Cent.git. If not using git download the project using git clone https://github.com/ankurp/Cent.git in your project folder.
  2. Open the Cent folder. Drag Cent.xcodeproj, inside the Cent folder, into the file navigator of your Xcode project.
  3. In Xcode, navigate to the target configuration window by clicking on the blue project icon, and selecting the application target under the "Targets" heading in the sidebar.
  4. In the tab bar at the top of that window, open the "Build Phases" panel.
  5. Expand the "Link Binary with Libraries" group, and add Cent.framework.
  6. In your project file import Cent and you can call all of the helper functions.

Support for Xcode and Swift

  • For Xcode 9 (Swift 4) user version 7.0.0
  • For Xcode 8 (Swift 3) user version 6.0.4
  • For Xcode 7 (Swift 2) use version 4.1.0 or 5.2.0
  • For Xcode 6.3 (Swift 1.2) use version 3.0.3
  • For Xcode 6.1 and 6.2 (Swift 1.1) use version 2.2.0


  • If you need help, use gitter.im or post a question on Stack Overflow with tag dollar.swift.
  • If you'd like to ask a general question, use Stack Overflow.
  • If you found a bug, open an issue.
  • If you have a feature request, open an issue.
  • If you want to contribute, submit a pull request.

Cent Usage

Array Extensions

<< elem: Element -> [Element]

Overloaded operator to append element to an array or append elements from another array into the first array. Return array with the element appended in the end.

var array = [1, 2, 3]
array << 4
=> [1, 2, 3, 4]
array << [5, 6]
=> [1, 2, 3, 4, 5, 6]

at(indexes: Int...) -> [Element]

Creates an array of elements from the specified indexes, or keys, of the collection.

let array = ["foo", "spam", "bar", "eggs"]
let some = array.at(1, 3)
=> ["spam", "eggs"]

each(callback: (Element) -> ()) -> [Element]

For each item in the array invoke the callback by passing the elem

let array = ["foo", "spam", "bar", "eggs"]
array.each {
=> ["foo", "spam", "bar", "eggs"]

eachWithIndex(callback: (Int, Element) -> ()) -> [Element]

For each item in the array invoke the callback by passing the elem along with the index

let array = ["foo", "spam", "bar", "eggs"]
array.each { (index, elem)
  print("\(index) - \(elem)")
=> ["foo", "spam", "bar", "eggs"]

cycle<U>(times: Int, callback: (Element) -> U)

Cycles through the array definetly or indefinetly passing each element into the callback function. The second parameter is to specify how many times to cycle through the array. If left out it will cycle indefinetly.

[1, 2, 3].cycle(2) {
// Prints the following

[1, 2, 3].cycle {
// Cycles in an infinite loop

every(callback: (Element) -> Bool) -> Bool

Checks if the given callback returns true value for all items in the array.

["angry", "hungry"].every { (a: String) -> (Bool) in 
=> true

indexOf<T: Equatable>(value: T) -> Int

Gets the index at which the first occurrence of value is found.

let array = ["foo", "spam", "bar", "eggs"]
=> 1
=> nil

fetch(index: Int, orElse: T? = .None) -> T!

Get element from an array at the given index which can be negative to find elements from the end of the array. A default value can be returned if indexing out of bounds.

let arr = [1, 2, 3, 4, 5, 6, 7, 8]
=> nil

arr.fetch(100, orElse: 42)
=> 42

=> 8

findIndex(callback: (Element) -> Bool) -> Int?

This method is like find except that it returns the index of the first element that passes the callback check.

let ind: int? = ["foo", "bar", "spam", "eggs"].findIndex {
  $0.length == 4
ind! == 2 
=> true

findLastIndex(callback: (Element) -> Bool) -> Int?

This method is like findIndex except that it iterates over elements of the array from right to left.

let ind: int? = ["foo", "bar", "spam", "eggs"].findLastIndex {
  $0.length == 4 
ind! == 3 
=> true

first() -> Element?

Gets the first element in the array.

let first = ["foo", "bar"].first()
=> "foo"

flatten() -> [Element]

Flattens a nested array of any depth.

let unFlattened = ["foo", ["bar"], [["spam"]], [[["eggs"]]] ]
let flattened = unFlattened.flatten() 
=> ["foo", "bar", "spam", "eggs"]

get(index: Int) -> Element?

Get element at index

let element = ["foo", "bar"].get(0)
=> "foo"

let nothing = ["foo", "bar"].get(1000)
=> nil

initial(numElements: Int? = 1) -> [Element]

Gets all but the last element or last n elements of an array.

let initial = ["foo", "bar", "spam"].initial(2) 
=> ["foo"]

last() -> Element?

Gets the last element from the array.

let last = ["foo", "bar"].last() 
=> "bar"

rest(numElements: Int? = 1) -> [Element]

The opposite of initial this method gets all but the first element or first n elements of an array.

let rest = ["foo", "bar", "spam"].rest(2)
=> ["spam"]

min<T: Comparable>() -> T?

Retrieves the minimum value in an array.

let min = [ 0, 1, 2 ].min()
=> 0

max<T: Comparable>() -> T?

Retrieves the maximum value in an array.

let max = [ 0, 1, 2].max()
=> 2

remove<T: Equatable>(value: T) -> T?

Remove element from array

var arr = ["A", "B", "C", "D", "E"]
=> ["A", "C", "D", "E"]

contains<T:Equatable>(value: T) -> Bool

Checks if a given value is present in the array.

var arr = ["A", "B", "C", "D", "E"]
=> true
=> false

zipObject<T>(values: [T]) -> [Element:T]

Creates an object composed from arrays of keys and values.

let keys = ["A", "B", "C"]
let vals = [1,2,3]
=> ["A":1,"B":2,"C":3]


Checks if the array has one or more elements.

let arr = [1,2,3]
=> true

Character Extensions

"A".description -> String

Get string description of Character

let ch: Character = "A"
let str = ch.description
=> "A"

"A".ord -> Int

Get int representation of character

=> 65

Date Extensions

Date.from(#year: Int, month: Int, day: Int) -> NSDate

Returns a new Date given the year month and day

let date = Date.from(2014, 1, 1) 
=> "Jan 1, 2014, 12:00 AM"

Date.from(#unix: Double) -> NSDate

Returns a new Date given the unix timestamp (timeIntervalSince1970)

let date = Date.from(unix: 1_388_552_400.0)
=> "Jan 1, 2014, 12:00 AM"

Date.parse(dateStr: String, format: String = "yyyy-MM-dd") -> NSDate

Parses the date based on the format and return a new Date

let parsedDate = Date.parse("2014-01-01", format: "yyyy-MM-dd")
=> "Jan 1, 2014, 12:00 AM"

Date.unix(date: NSDate = NSDate()) -> Double

Returns the unix timestamp of the date passed in or the current unix timestamp

let currentUnix = Date.unix()
=> 1,388,552,400.0

var otherNSDate = Date()
let otherUnix = Date.unix(otherDate)
=> 1,388,552,400.0

Int.hour.fromNow et al.

Use the following syntax to calculate dates and times based on the user's current calendar.

=> "Apr 10, 2015, 11:51 AM"
=> "Apr 11, 2015, 3:51 PM"

Dictionary Extensions

merge<K, V>(dictionaries: Dictionary<K, V>...)

Merges the dictionary with dictionaries passed. The latter dictionaries will override values of the keys that are already set

var dic = ["foo": "bar"] 
let anotherDic = ["foo": "baz", "spam": "eggs"]
=> ["foo": "baz", "spam": "eggs"]

Int Extensions

times(callback: (Int) -> ())

Invoke a callback n times with callback that takes index

5.times { print("Na") } 
=> "NaNaNaNaNa"

times (function: () -> ())

Invoke a callback n times

5.times { (a: Int) -> () in print("\(a) ") } 
=> 0 1 2 3 4  

char -> Character

Get ASCII character from integer

=> "A"


Check if int is even

=> true

=> false


Check if int is odd

=> true

=> false

digits() -> [Int]

Splits the int into array of digits

=> [4, 2, 0, 8]

lcm() -> Int

LCM method return least common multiple with number passed

=> 30

=> 9

gcd() -> Int

GCD method return greatest common denominator with number passed

=> 1

=> 3

random() -> Int

Returns random number from 0 upto but not including value of integer

=> 2

=> 1

factorial() -> Int

Returns factorial of integer

=> 6

=> 1

isIn(interval) -> Bool

Returns true if i is in interval or range

=> true

=> false

next() -> Int

Get the next int

=> 11

prev() -> Int

Get the previous int

=> 9

upTo(limit: Int, callback: () -> ())

Invoke the callback from int up to and including limit

3.upTo(5) {
Prints "HiHiHi"

downTo(limit: Int, callback: () -> ())

Invoke the callback from int down to and including limit

3.downTo(0) {
Prints "HiHiHiHi"

String Extensions


Get the length of the string

=> 5


Get the camel case representation of the string

"__Dollar and cent-- dollarANDCent".camelCase
=> "dollarAndCentDollarAndCent"


Get the kebab case representation of the string

"__Dollar and cent-- dollarANDCent".kebabCase
=> "dollar-and-cent-dollar-and-cent"


Get the snake case representation of the string

"__Dollar and cent-- dollarANDCent".snakeCase
=> "dollar_and_cent_dollar_and_cent"


Get the start case representation of the string

"__Dollar and cent-- dollarANDCent".startCase
=> "Dollar And Cent Dollar And Cent"

=~ str: String -> Bool

Does a regex match of whether regex string on the right is matches the string on the left

"Dollar" =~ "oll"
=> true

* n: Int -> String

Get string concatenated n times

"Hi Swift! " * 3
=> "Hi Swift! Hi Swift! Hi Swift! "

[i: Int] -> Character?

Get character at a subscript

"Hello World"[6] == "W"
=> true

=> nil

[str: String] -> String?

Returns the substring based on the first regex match passed in the subscript

let proj = "Dollar and Cent"
proj["^.+[^and Cent]"]
=> {Some: "Dollar"}

[r: Range<Int>] -> String

Get substring using subscript notation and by passing a range

"Hello World"[0..<5] == "Hello" 
=> true

indexOf(char: Character) -> Int?

Get the start index of character

"hello world".indexOf(Character("o"))!
=> 4

indexOf(str: String) -> Int?

Get the start index of string

"hello world".indexOf("llo")!
=> 2

"hello world".indexOf("illo")
=> nil

indexOf(pattern: String) -> Int?

Get the start index of regex pattern inside the string

"hello world".indexOf(".llo")!
=> 1

split(delimiter: Character) -> [String]

Get an array from string split using the delimiter character

"Hello World".split(" ") 
=> ["Hello", "World"]

lstring() -> String

Get string without leading spaces

let leadingSpace = "  Hello"
=> "Hello"

rstring() -> String

Get string without trailing spaces

let trailingSpace = "Hello   "
=> "Hello"

strip() -> String

Get string without leading or trailing spaces

let spaces = "   Hello   "
=> "Hello"



Init with regex pattern as string

Regex.init("^Hello.World$") // Regex that matches "Hello World"

matches(testStr: String) -> [AnyObject]

Return matches based on String passed.

let re = Regex.init("^Hello.World$")
re.matches("Hello World")

test(testStr: String) -> Bool

let re = Regex.init("^Hello.World$")
re.test("Hello World")
=> true

=> false

escapeStr(str: String) -> String

Escape string with regex characters

=> "Hello\.World"

Range Extensions

equals - ==

Check the equality of two ranges

(1...5) == (1...5) 
=> true

(1..<5) == (1...5) 
=> false

eachWithIndex(callback: (T) -> ())

For each index in the range invoke the callback by passing the item in range

(1...5).eachWithIndex { (a: Int) -> () in print("\(a)") } 
=> 12345

each(callback: () -> ())

For each index in the range invoke the callback

(1...5).each { print("Na") } 
=> "NaNaNaNaNa"


If you are interested in contributing checkout CONTRIBUTING.md