Swift – Remove an Element from Array

Swift – Remove Element from Array

In Swift, you can remove an array element by its index, remove the first or last element, remove a range of elements, or remove elements that match a condition.

To remove an element at a specific index, use the remove(at:) method.

array.remove(at: index)

The method modifies the original array and returns the removed element. Swift arrays use zero-based indexing, so the first element is at index 0, the second is at index 1, and so on.

If you describe an element by its human-readable position, subtract one to obtain its array index. For example, the fourth element is stored at index 3.

Remove an Element at a Specific Swift Array Index

In this example, we have an Integer array of size 7 and we shall delete 4th element using remove(at:index) method.

main.swift

var numbers:[Int] = [2, 3, 5, 7, 11, 13, 17]

numbers.remove(at: 3)

numbers.forEach { number in
    print("\(number)")
}

Output

2
3
5
11
13
17

The value 7 is the fourth element, so it is removed using index 3. The elements after it shift one position toward the beginning of the array.

Get the Element Returned by remove(at:)

remove(at:) returns the element that was removed. Assign the result to a variable when the deleted value is needed later.

var colors = ["Red", "Green", "Blue"]

let removedColor = colors.remove(at: 1)

print(removedColor)
print(colors)

Output

Green
["Red", "Blue"]

Avoid an Index Out of Range Error

The index passed to remove(at:) must be valid. Passing a negative index or an index equal to or greater than array.count causes a runtime error.

Use the array’s indices collection to check a variable index before removing the element.

var numbers = [10, 20, 30]
let indexToRemove = 2

if numbers.indices.contains(indexToRemove) {
    numbers.remove(at: indexToRemove)
}

print(numbers)

Output

[10, 20]

Remove the Last Element from a Swift Array

In this example, we have an Integer array of size 4 and we shall delete the last element using remove(at: array.count-1) method.

main.swift

var months:[String] = ["January", "February", "March", "April"]

months.remove(at: months.count-1)

months.forEach { month in
    print("\(month)")
}

Output

January
February
March

Swift also provides removeLast(), which expresses this operation more directly. Do not call it on an empty array.

var months = ["January", "February", "March", "April"]

let removedMonth = months.removeLast()

print(removedMonth)
print(months)

Output

April
["January", "February", "March"]

Remove the First Element from a Swift Array

In this example, we have a String Array and we shall remove the first element using remove(at:0) method.

main.swift

var months:[String] = ["January", "February", "March", "April"]

months.remove(at: 0)

months.forEach { month in
    print("\(month)")
}

Output

February
March
April

You can write the same operation using removeFirst(). This method returns the removed element and must not be called when the array is empty.

var months = ["January", "February", "March", "April"]

let removedMonth = months.removeFirst()

print(removedMonth)
print(months)

Output

January
["February", "March", "April"]

Remove a Swift Array Element by Value

Swift arrays remove elements by index rather than directly by value. To remove the first matching value, find its index with firstIndex(of:) and then pass that index to remove(at:).

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

if let index = fruits.firstIndex(of: "Banana") {
    fruits.remove(at: index)
}

print(fruits)

Output

["Apple", "Orange", "Banana"]

Only the first matching "Banana" is removed. This approach requires the array element type to support equality comparison.

Remove All Matching Elements with removeAll(where:)

Use removeAll(where:) when every element matching a condition should be deleted from the original array.

var numbers = [1, 2, 3, 4, 5, 6]

numbers.removeAll { number in
    number.isMultiple(of: 2)
}

print(numbers)

Output

[1, 3, 5]

The closure returns true for elements that should be removed. In this example, all even numbers are deleted.

Filter a Swift Array Without Modifying the Original

Use filter when you want to create a new array containing only the elements that should remain. Unlike removeAll(where:), filter does not mutate the source array.

let numbers = [1, 2, 3, 4, 5, 6]
let oddNumbers = numbers.filter { !$0.isMultiple(of: 2) }

print(numbers)
print(oddNumbers)

Output

[1, 2, 3, 4, 5, 6]
[1, 3, 5]

Remove Multiple Elements from a Swift Array

Use removeSubrange(_:) to remove a continuous range of array elements. The range must be within the array’s valid indices.

var letters = ["A", "B", "C", "D", "E"]

letters.removeSubrange(1...3)

print(letters)

Output

["A", "E"]

Choose the Correct Swift Array Removal Method

Required operation	Swift method
Remove an element at a known index	remove(at:)
Remove the first element	removeFirst()
Remove the last element	removeLast()
Remove the first matching value	firstIndex(of:) with remove(at:)
Remove all elements matching a condition	removeAll(where:)
Create a new array excluding some elements	filter
Remove a continuous range	removeSubrange(_:)
Remove every element	removeAll()

Frequently Asked Questions About Removing Swift Array Elements

How do I remove an array element safely when the index may be invalid?

Check the index with array.indices.contains(index) before calling remove(at:). This prevents an index-out-of-range runtime error.

How do I remove the first occurrence of a value from a Swift array?

Use firstIndex(of:) to locate the value. If it returns an index, pass that index to remove(at:).

How do I remove every occurrence of a value from a Swift array?

Use removeAll { $0 == value } to modify the original array, or use filter { $0 != value } to produce a new array.

What happens to the remaining elements after remove(at:)?

Elements that appear after the removed index shift toward the beginning of the array. Their indices therefore change.

Can removeFirst() or removeLast() be used on an empty array?

No. Calling either method on an empty array causes a runtime error. Check isEmpty first when the array may contain no elements.

Swift Array Removal Summary

Use remove(at:) when the target index is known. Use removeFirst() or removeLast() for an endpoint, firstIndex(of:) for the first matching value, and removeAll(where:) for every element that matches a condition. Validate variable indices before removal to avoid runtime errors.