Remove Specific Array Element, Equal to String - Swift

Is there no easy way to remove a specific element from an array, if it is equal to a given string? The workarounds are to find the index of the element of the array you wish to remove, and then removeAtIndex, or to create a new array where you append all elements that are not equal to the given string. But is there no quicker way?

You can use filter() to filter your array as follow

var strings = ["Hello","Playground","World"]

strings = strings.filter { $0 != "Hello" }

print(strings)   // "["Playground", "World"]\n"

edit/update:

Xcode 10 • Swift 4.2 or later

You can use the new RangeReplaceableCollection mutating method called removeAll(where:)

var strings = ["Hello","Playground","World"]

strings.removeAll { $0 == "Hello" }

print(strings)   // "["Playground", "World"]\n"

If you need to remove only the first occurrence of an element we ca implement a custom remove method on RangeReplaceableCollection constraining the elements to Equatable:

extension RangeReplaceableCollection where Element: Equatable {
    @discardableResult
    mutating func removeFirst(_ element: Element) -> Element? {
        guard let index = firstIndex(of: element) else { return nil }
        return remove(at: index)
    }
}

---

Or using a predicate for non Equatable elements:

extension RangeReplaceableCollection {
    @discardableResult
    mutating func removeFirst(where predicate: @escaping (Element) throws -> Bool) rethrows -> Element? {
        guard let index = try firstIndex(where: predicate) else { return nil }
        return remove(at: index)
    }
}

---

var strings = ["Hello","Playground","World"]
strings.removeFirst("Hello")
print(strings)   // "["Playground", "World"]\n"
strings.removeFirst { $0 == "Playground" }
print(strings)   // "["World"]\n"

Using filter like suggested above is nice. But if you want to remove only one occurrence of a value or you assume there are no duplicates in the array and you want a faster algorithm, use this:

EDIT: Swift 5 Update

if let index = array.firstIndex(of: "stringToRemove") {
    array.remove(at: index)
} else {
    // not found
}

Thanks @Thomas Mary.

Swift 3 and 4

if let index = array.index(of: "stringToRemove") {
    array.remove(at: index)
} else {
    // not found
}

It's not clear if by quicker you mean in terms of execution time or amount of code.

In the latter case you can easily create a copy using the filter method. For example, given the following array:

let array = ["1", "2", "3", "4", "5"]

you can create a copy with all elements but "2" as:

let filteredArray = array.filter { $0 != "2" }

You'll want to use filter(). If you have a single element (called say obj) to remove, then the filter() predicate will be { $0 != obj }. If you do this repeatedly for a large array this might be a performance issue. If you can defer removing individual objects and want to remove an entire sub-array then use something like:

var stringsToRemove : [String] = ...
var strings : [String] = ...

strings.filter { !contains(stringsToRemove, $0) }

for example:

 1> ["a", "b", "c", "d"].filter { !contains(["b", "c"], $0) }
$R5: [String] = 2 values {
  [0] = "a"
  [1] = "d"
}

You could use filter() in combination with operator overloading to produce an easily repeatable solution:

func -= (inout left: [String], right: String){
    left = left.filter{$0 != right}    
}

var myArrayOfStrings:[String] = ["Hello","Playground","World"]

myArrayOfStrings -= "Hello"

print(myArrayOfStrings)   // "[Playground, World]"

if you need to delete subArray from array then this is a perfect solution using Swift3:

var array = ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j"]            
let subArrayToDelete = ["c", "d", "e", "ee"]
array = array.filter{ !subArrayToDelete.contains($0) }
print(array) // ["a", "b", "f", "g", "h", "i", "j"]

this is better for your performance rather than deleting one by one.

btw even faster solution is (but it will rearrange items in the final array):

array = Array(Set(array).subtracting(subArrayToDelete))

var ra = ["a", "ab", "abc", "a", "ab"]

print(ra)                               // [["a", "ab", "abc", "a", "ab"]

ra.removeAll(where: { $0 == "a" })

print(ra)                               // ["ab", "abc", "ab"]

Simple loop over Array

var array = ["Apple","Banana","Orange"]

for (index,value) in array.enumerated(){
    if value == "Banana"{
    array.remove(at: index)
}