Array.append() / insert() / remove()

// Adds an element to the end of the array.
array.append(element)

// Inserts an element at the specified index.
array.insert(element, at: index)

// Removes the element at the specified index.
array.remove(at: index)

// Removes the last element.
array.removeLast()

// Removes the first element.
array.removeFirst()

// Removes all elements.
array.removeAll()

var fruits = ["apple", "orange", "grape"]

// Adds an element to the end.
fruits.append("peach")
print(fruits) // ["apple", "orange", "grape", "peach"]

// Adds all elements from another array.
fruits.append(contentsOf: ["strawberry", "melon"])
print(fruits) // ["apple", "orange", "grape", "peach", "strawberry", "melon"]

// Inserts an element at index 1.
fruits.insert("banana", at: 1)
print(fruits) // ["apple", "banana", "orange", ...]

// Removes the element at index 2.
let removed = fruits.remove(at: 2)
print(removed) // "orange"

// Removes the last element.
fruits.removeLast()
print(fruits.last ?? "") // "strawberry"

// Removes all elements.
fruits.removeAll()
print(fruits.isEmpty) // true

Because Swift arrays are value types (structs), you must declare them with var to modify them. Calling any of these methods on an array declared with let results in a compile error.

remove(at:) returns the removed element, making it convenient when you need to both delete and retrieve a value at the same time. Specifying an index that does not exist causes a runtime crash (Index out of range), so always check the array's size beforehand.

For searching elements, see contains() / firstIndex(). For transforming elements, see map() / compactMap().